Tertiary alcohol imidazopyrazine BTK inhibitors

ABSTRACT

The present invention provides Bruton&#39;s Tyrosine Kinase (Btk) inhibitor compounds according to Formula I, or pharmaceutically acceptable salts thereof, Formula I or to pharmaceutical compositions comprising these compounds and to their use in therapy. In particular, the present invention relates to the use of Btk inhibitor compounds of Formula I in the treatment of Btk mediated disorders.

FIELD OF THE INVENTION

The present invention relates to Btk inhibitor compounds, topharmaceutical compositions comprising these compounds and to their usein therapy. In particular, the present invention relates to the use ofBtk inhibitor compounds in the treatment of Bruton's Tyrosine Kinase(Btk) mediated disorders.

BACKGROUND OF THE INVENTION

B lymphocyte activation is key in the generation of adaptive immuneresponses. Derailed B lymphocyte activation is a hallmark of manyautoimmune diseases and modulation of this immune response is thereforeof therapeutic interest. Recently the success of B cell therapies inautoimmune diseases has been established. Treatment of rheumatoidarthritis (RA) patients with Rituximab (anti-CD20 therapy) is anaccepted clinical therapy by now. More recent clinical trial studiesshow that treatment with Rituximab also ameliorates disease symptoms inrelapsing remitting multiple sclerosis (RRMS) and systemic lupuserythematosus (SLE) patients. This success supports the potential forfuture therapies in autoimmune diseases targeting B cell immunity.

Bruton tyrosine kinase (Btk) is a Tec family non-receptor proteinkinase, expressed in B cells and myeloid cells. The function of Btk insignaling pathways activated by the engagement of the B cell receptor(BCR) and FcεR1 on mast cells is well established. In addition, afunction for Btk as a downstream target in Toll-like receptor signalingwas suggested.

Functional mutations in Btk in human results in the primaryimmunodeficiency disease called XLA which is characterized by a defectin B cell development with a block between pro- and pre-B cell stage.This results in an almost complete absence of B lymphocytes in humancausing a pronounced reduction of serum immunoglobulin of all classes.These finding support the key role for Btk in the regulation of theproduction of auto-antibodies in autoimmune diseases. In addition,regulation of Btk may affect BCR-induced production of pro-inflammatorycytokines and chemokines by B cells, indicating a broad potential forBtk in the treatment of autoimmune diseases.

With the regulatory role reported for Btk in FcεR-mediated mast cellactivation, Btk inhibitors may also show potential in the treatment ofallergic responses [Gilfillan et al, Immunological Reviews 288 (2009) pp149-169].

Furthermore, Btk is also reported to be implicated in RANKL-inducedosteoclast differentiation [Shinohara et al, Cell 132 (2008) pp 794-806]and therefore may also be of interest for the treatment of boneresorption disorders.

Other diseases with an important role for dysfunctional B cells are Bcell malignancies. Indeed anti-CD20 therapy is used effectively in theclinic for the treatment of follicular lymphoma, diffuse large B-celllymphoma and chronic lymphocytic leukemia [Lim et al, Haematologica, 95(2010) pp 135-143]. The reported role for Btk in the regulation ofproliferation and apoptosis of B cells indicates there is potential forBtk inhibitors in the treatment of B cell lymphomas as well. Inhibitionof Btk seems to be relevant in particular for B cell lymphomas due tochronic active BCR signaling [Davis et al, Nature, 463 (2010) pp 88-94].

Some classes of Btk inhibitor compounds have been described as kinaseinhibitors, e.g. Imidazo[1,5-f][1,2,4]triazine compounds have beendescribed in WO2005097800 and WO2007064993. Imidazo[1,5-a]pyrazinecompounds have been described in WO2005037836 and WO2001019828 as IGF-1Renzyme inhibitors.

Some of the Btk inhibitors reported are not selective over Src-familykinases. With dramatic adverse effects reported for knockouts ofSrc-family kinases, especially for double and triple knockouts, this isseen as prohibitive for the development of Btk inhibitors that are notselective over the Src-family kinases.

Both Lyn-deficient and Fyn-deficient mice exhibit autoimmunity mimickingthe phenotype of human lupus nephritis. In addition, Fyn-deficient micealso show pronounced neurological defects. Lyn knockout mice also showan allergic-like phenotype, indicating Lyn as a broad negative regulatorof the IgE-mediated allergic response by controlling mast cellresponsiveness and allergy-associated traits [Odom et al, J. Exp. Med.,199 (2004) pp 1491-1502]. Furthermore, aged Lyn knock-out mice developsevere splenomegaly (myeloid expansion) and disseminatedmonocyte/macrophage tumors [Harder et al, Immunity, 15 (2001) pp603-615]. These observations are in line with hyperresponsive B cells,mast cells and myeloid cells, and increased Ig levels observed inLyn-deficient mice. Female Src knockout mice are infertile due toreduced follicle development and ovulation [Roby et al, Endocrine, 26(2005) pp 169-176]. The double knockouts Src^(−/−)Fyn^(−/−) andSrc^(−/−)Yes^(−/−) show a severe phenotype with effects on movement andbreathing. The triple knockouts Src^(−/−)Fyn^(−/−)Yes^(−/−) die at day9.5 [Klinghoffer et al, EMBO J., 18 (1999) pp 2459-2471]. For the doubleknockout Src^(−/−)Hck^(−/−), two thirds of the mice die at birth, withsurviving mice developing osteopetrosis, extramedullary hematopoiesis,anemia, leukopenia [Lowell et al, Blood, 87 (1996) pp 1780-1792].

Hence, an inhibitor that inhibits multiple or all kinases of theSrc-family kinases simultaneously may cause serious adverse effects.

SUMMARY OF THE INVENTION

The present invention provides compounds which inhibit Btk activity,their use for treatment of Btk mediated diseases and disorders, inparticular autoimmune diseases and inflammatory diseases, as well aspharmaceutical compositions comprising such compounds and pharmaceuticalcarriers.

DETAILED DESCRIPTION Definitions

The terms used herein have their ordinary meaning and the meaning ofsuch terms is independent at each occurrence thereof. Thatnotwithstanding, and except where stated otherwise, the followingdefinitions apply throughout the specification and claims. Chemicalnames, common names, and chemical structures may be used interchangeablyto describe the same structure. These definitions apply regardless ofwhether a term is used by itself or in combination with other terms,unless otherwise indicated. Hence, the definition of “alkyl” applies to“alkyl” as well as the “alkyl” portions of “hydroxyalkyl,”“fluoroalkyl,” “alkoxy”, “alkylene”, etc.

As used herein, and throughout this disclosure, the following terms,unless otherwise indicated, shall be understood to have the followingmeanings:

The term “alkyl,” as used herein, refers to an aliphatic hydrocarbongroup having one of its hydrogen atoms replaced with a bond having thespecified number of carbon atoms. In different embodiments, an alkylgroup contains, for example, from 1 to 6 carbon atoms (1-6C)alkyl orfrom 1 to 3 carbon atoms (1-3C)alkyl. In one embodiment, an alkyl groupis linear.

In another embodiment, an alkyl group is branched. Non-limiting examplesof alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl,sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, isopentyl,n-hexyl, isohexyl and neohexyl.

“Alkoxy” refers to an alkyl-O— group represented by a linear or branchedalkyl group of indicated number of carbon atoms attached through anoxygen bridge; for example “(1-3C)Alkoxy” includes —OCH₃, —OCH₂CH₃,—OCH(CH₃)₂, and the like.

Unless otherwise specifically noted as only “unsubstituted” or only“substituted”, alkyl groups are unsubstituted or substituted with 1 to 3substituents on each carbon atom.

The term “amount effective” or “effective amount” as used herein, refersto an amount of the compound of Formula I and/or an additionaltherapeutic agent, or a composition thereof, that is effective inproducing the desired therapeutic, ameliorative, inhibitory orpreventative effect when administered to a subject suffering from aBTK-mediated disease or disorder. In the combination therapies of thepresent invention, an effective amount can refer to each individualagent or to the combination as a whole, wherein the amounts of allagents administered are together effective, but wherein the componentagent of the combination may not be present individually in an effectiveamount.

The term “cycloalkyl,” as used herein, refers to a saturated mono- ormulticyclic ring system containing up to 10 ring carbon atoms, and noheteroatom. In a like manner the term “(C₃₋₆) cycloalkyl” or(3-6C)cycloalkyl” refers to a saturated ring having from 3 to 6 ringcarbon atoms. Non-limiting examples of monocyclic cycloalkyls includecyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. In one embodiment,the cycloalkyl is cyclopropyl.

The term “heterocycloalkyl”, as used herein, refers to a monocyclic ringhaving a 5- or 6-membered saturated ring system having 1 or 2heteroatoms selected from N and/or O such that the heterocycloalkyl maybe linked through a carbon or nitrogen atom. The heterocycloalkyl may benon-limiting examples of heterocycloalkyls include tetrahydrofuran,tetrahydropyran and piperidine. Additionally, heterocycloalkyl may referto a multicyclic ring system having up to 10 carbon atoms with 1 or 2heteroatoms selected from N and/or O.

The multicyclic ring system of the cycloalkyl and heterocycloalkylgroups may be composed of two or more rings that may be joined togetherto form a bridged ring system. Non-limiting examples of bridged groupsinclude C₆-C₉ bridged cycloalkyls such as, for example, the following:

or any of these bridged groups substituted with 1 or 2 heteroatomsselected from N or O.

The term “halogen”, as used herein, refers to fluorine, chlorine,bromine or iodine. Fluorine, chlorine or bromine being preferredhalogens; fluorine being more preferred.

The term “C₀” as employed in expressions such as “(C₀₋₆)alkylene” meansa direct covalent bond; or when employed in expressions such as“(C₀₋₆)alkyl” means hydrogen. Similarly, when an integer defining thepresence of a certain number of atoms in a group is equal to zero, itmeans that the atoms adjacent thereto are connected directly by a bond;for example, in the structure

wherein s is an integer equal to zero, 1 or 2, the structure is

when s is zero; or it means that the indicated atom is absent; forexample —S(O)₀— means —S—.

Unless expressly stated to the contrary, all ranges cited herein areinclusive. For example, a heterocycloalkyl described as containing from“1 to 4 heteroatoms” means the heterocycloalkyl can contain 1, 2, 3 or 4heteroatoms.

When any variable occurs more than one time in any constituent or in anyformula depicting and describing compounds of the invention, itsdefinition on each occurrence is independent of its definition at everyother occurrence. Also, combinations of substituents and/or variablesare permissible only if such combinations result in stable compounds.

For variable definitions containing terms having repeated terms, e.g.,(CRiRj)_(r), where r is the integer 2, Ri is a defined variable, and Rjis a defined variable, the value of Ri may differ in each instance inwhich it occurs, and the value of Rj may differ in each instance inwhich it occurs. For example, if Ri and Rj are independently selectedfrom the group consisting of methyl, ethyl, propyl and butyl, then(CRiRj)₂ can be

As used herein, the term “X_(a)-X_(b)”, shall have the same meaning asthe term “X_(a-b)” or “(a-bX)”, wherein X is any atom and a and b areany integers. For example, “C₁-C₄” shall have the same meaning as “C₁₋₄”or “(1-4C)”. Additionally, when referring to a functional groupgenerically, “A^(x)” shall have the same meaning, and be interchangeablewith, “AX”, wherein “A” is any atom and “x” or “X” are any integer. Forexample, “R¹” shall have the same meaning, and be interchangeable with,“R1”.

In the above definitions with multifunctional groups, the attachmentpoint is at the last group. For example, the term (C₁₋₃)alkoxycarbonylrefers to, e.g.

and the term (C₁₋₄)alkylcarbonyloxy refers to, e.g.

The term “oxo” as used herein, refers to an oxygen atom that is bondedto the compound having Formula I with a double bond.

The term “purified” as used herein, refers to the physical state of acompound after the compound has been isolated through a syntheticprocess (e.g., from a reaction mixture), from a natural source, or acombination thereof. The term “purified” also refers to the physicalstate of a compound after the compound has been obtained from apurification process or processes described herein or well-known to theskilled artisan (e.g., chromatography, recrystallization, and the like),in sufficient purity to be characterizable by standard analyticaltechniques described herein or well-known to the skilled artisan.

The term “substituted”, as used herein, means that one or more hydrogenson the designated atom/atoms is/are replaced with a selection from theindicated group, provided that the designated atom's normal valencyunder the existing circumstances is not exceeded, and that thesubstitution results in a stable compound. Combinations of substituentsand/or variables are permissible only if such combinations result instable compounds. “Stable compound” or “stable structure” is defined asa compound or structure that is sufficiently robust to survive isolationto a useful degree of purity from a reaction mixture, and formulationinto an efficacious therapeutic agent.

The term “optionally substituted” means that a compound may or may notbe substituted with the specified groups, radicals or moieties.

A “subject” is a human or non-human mammal. In one embodiment, a subjectis a human. In another embodiment, the subject is a chimpanzee.

In the above definitions with multifunctional groups, the attachmentpoint is at the last group, unless otherwise specified on thesubstituent group by a dash. A dash on the substituent group would thenrepresent the point of attachment.

It should be noted that any carbon as well as heteroatom withunsatisfied valences in the text, schemes, examples and tables herein isassumed to have the sufficient number of hydrogen atom(s) to satisfy thevalences.

Compounds of the Invention

The present invention provides Btk inhibitor compounds according toFormula I or pharmaceutically acceptable salts thereof

wherein:n is 0, 1 or 2;R¹ is (1-3C)alkyl, optionally substituted with one, two or threehalogen;R₂ is independently selected from the group consisting of methoxy,ethoxy, halogen, and hydroxyl;R₃ is hydrogen, halogen or C(1-3) alkyl;X is selected from the group consisting of:

a) cycloalkyl; and

b) heterocycloalkyl;

each optionally substituted with one to four R⁴,

wherein R⁴ is hydrogen, oxo, fluoro or (1-6C)alkyl.

In another aspect the invention relates to the compound having FormulaI,

wherein

X is selected from the group consisting of:

-   -   a) cyclopropyl;    -   b) cyclopentyl;    -   c) cyclohexyl;    -   d) bicyclo[2.2.2]octanyl;    -   e) bicyclo[3.2.1]octanyl;    -   f) bicyclo[2.2.1]heptanyl;    -   g) bicyclo[3.2.2]nonanyl;    -   h) bicyclo[3.1.0]hexanyl;    -   i) tricyclo[3.2.2.0^(2,4)]nonanyl; and    -   j) tetrahydropyranyl.

The present invention also provides Btk inhibitor compounds according toFormula Ia or pharmaceutically acceptable salts thereof

wherein:R¹ is (1-3C)alkyl, optionally substituted with one, two or threehalogen;R² is hydrogen or (1-3C)alkoxy;R³ is hydrogen or halogen;X is selected from the group consisting of:

a) cycloalkyl; and

b) heterocycloalkyl;

each optionally substituted with one to four R⁴,

wherein R⁴ is hydrogen, oxo, fluoro or (1-6C)alkyl.

In one aspect the invention relates to the compound having Formula Ia,wherein

X is selected from the group consisting of:

-   -   a) cyclopropyl;    -   b) cyclopentyl;    -   c) cyclohexyl;    -   d) bicyclo[2.2.2]octanyl;    -   e) bicyclo[3.2.1]octanyl;    -   f) bicyclo[2.2.1]heptanyl;    -   g) bicyclo[3.2.2]nonanyl;    -   h) bicyclo[3.1.0]hexanyl;    -   i) tricyclo[3.2.2.0^(2,4)]nonanyl; and    -   j) tetrahydropyranyl.

In another aspect the invention relates to a compound having Formula Ib

or a pharmaceutically acceptable salt thereof.

In another aspect the invention relates to a compound having Formula Ic

or a pharmaceutically acceptable salt thereof.

In another aspect the invention relates to the compound having FormulaI, Ia, Ib and Ic, wherein R¹ is methyl, difluoromethyl ortrifluoromethyl.

In yet another aspect the invention relates to the compound havingFormula I, Ia, Ib, and Ic, wherein R² is ethoxy.

In a further aspect the invention relates to the compound having FormulaI, Ia, Ib, and Ic, wherein R³ is fluoro or chloro.

The invention also relates to those compounds wherein all specificdefinitions for R¹, R², R³, R⁴ and X, and all substituent groups in thevarious aspects of the inventions defined hereinabove, occur in anycombination within the definition of the Btk inhibitor compounds ofFormula I or pharmaceutically acceptable salts thereof.

Non-limiting examples of the compounds of the present invention include:

-   (R)-4-(8-amino-1-(4-(1-hydroxy-1-(3-(trifluoromethyl)phenyl)ethyl)phenyl)imidazo[1,5-a]pyrazin-3-yl)-1,4-dimethylcyclohexanecarboxylic    acid;-   4-[8-amino-1-(4-{(1S)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[2.2.2]octane-1-carboxylic    acid;-   4-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[2.2.2]octane-1-carboxylic    acid;-   (1S,3S)-3-[8-amino-1-(4-{(1S)-1-hydroxy-1-[3    (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentanecarboxylic    acid;-   (1S,3S)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentanecarboxylic    acid;-   4-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-2,5-dioxobicyclo[2.2.2]octane-1-carboxylic    acid;-   1-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]cyclopropanecarboxylic    acid;-   4-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[2.2.1]heptane-1-carboxylic    acid;-   5-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[3.2.2]nonane-1-carboxylic    acid;-   4-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]tetrahydro-2H-pyran-4-carboxylic    acid;-   (1S,3R)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,2,2-trimethylcyclopentanecarboxylic    acid;-   4-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-2,2,5,5-tetrafluorobicyclo[2.2.2]octane-1-carboxylic    acid;-   (1R,3S)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,2,2-trimethylcyclopentanecarboxylic    acid;-   (1S,3R)-3-[8-amino-1-(4-{(1S)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclohexanecarboxylic    acid;-   (1R,3S)-3-[8-amino-1-(4-{(1S)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclohexanecarboxylic    acid;-   (1S,3S)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,3-dimethylcyclopentanecarboxylic    acid;-   (1R,3S)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,3-dimethylcyclopentanecarboxylic    acid;-   (1S,3R)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,3-dimethylcyclopentanecarboxylic    acid;-   4-(8-amino-1-{2-ethoxy-4-[1-hydroxy-1-(3-methylphenyl)ethyl]phenyl}imidazo[1,5-a]pyrazin-3-yl)bicyclo[2.2.2]octane-1-carboxylic    acid;-   4-(8-amino-1-{2-ethoxy-4-[1-hydroxy-1-(3-methylphenyl)ethyl]phenyl}imidazo[1,5-a]pyrazin-3-yl)bicyclo[2.2.2]octane-1-carboxylic    acid;-   (1R,2R,5R)-5-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-2-(1-methylethyl)cyclohexanecarboxylic    acid;-   5-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]tricyclo[3.2.2.0˜2,4˜]nonane-1-carboxylic    acid;-   (1S,2S,5S)-5-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-2-(1-methylethyl)cyclohexanecarboxylic    acid;-   (1S,3R)-3-[8-amino-5-fluoro-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,2,2-trimethylcyclopentanecarboxylic    acid;-   (3-endo,8-syn)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[3.2.1]octane-8-carboxylic    acid;-   (3-exo,8-syn)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[3.2.1]octane-8-carboxylic    acid;-   (1S,3R)-3-[8-amino-1-(4-{(1R)-1-[3-(difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,2,2-trimethylcyclopentanecarboxylic    acid;-   (1S,3R)-3-[8-amino-1-(2-ethoxy-4-{(1S)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,2,2-trimethylcyclopentanecarboxylic    acid;-   (1S,3R)-3-[8-amino-5-chloro-1-(4-{(1R)-1-[3-(difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentanecarboxylic    acid;-   (1R,3S)-3-[8-amino-5-chloro-1-(4-{(1R)-1-[3-(difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentanecarboxylic    acid;-   (1S,3S)-3-[8-amino-5-chloro-1-(4-{(1R)-1-[3-(difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentanecarboxylic    acid;-   (1R,3R)-3-[8-amino-5-chloro-1-(4-{(1R)-1-[3-(difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentanecarboxylic    acid;-   4-[8-amino-1-(4-{(1R)-1-[3-(difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,4-dimethylcyclohexanecarboxylic    acid;-   (1S,3R)-3-[8-amino-1-(4-{(1R)-1-[3-(difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)-5-fluoroimidazo[1,5-a]pyrazin-3-yl]-1,2,2-trimethylcyclopentanecarboxylic    acid;-   (1R,3R,5S,6S)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[3.1.0]hexane-6-carboxylic    acid; and-   (1R,3R,5S,6R)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[3.1.0]hexane-6-carboxylic    acid.

The compounds of this invention include the salts, solvates, hydrates orprodrugs of the compounds. The use of the terms “salt”, “solvate”,“hydrate”, “prodrug” and the like, is intended to equally apply to thesalt, solvate, hydrate and prodrug of enantiomers, stereoisomers,rotamers, tautomers, positional isomers, or racemates of the inventivecompounds.

Salts

The Btk inhibitor compounds of the present invention, which can be inthe form of a free base, may be isolated from the reaction mixture inthe form of a pharmaceutically acceptable salt.

The compounds of Formula I can form salts which are also within thescope of this invention. Reference to a compound of Formula I herein isunderstood to include reference to pharmaceutically acceptable saltsthereof, unless otherwise indicated. The term “pharmaceuticallyacceptable salt(s)” or “salt”, as employed herein, denotes acidic saltsformed with inorganic and/or organic acids, as well as basic saltsformed with inorganic and/or organic bases. In addition, when a compoundof Formula I contains both a basic moiety, such as, but not limited to apyridine or imidazole, and an acidic moiety, such as, but not limited toa carboxylic acid, zwitterions (“inner salts”) may be formed and areincluded within the term “salt(s)” as used herein. Such acidic and basicsalts used within the scope of the invention are pharmaceuticallyacceptable (i.e., non-toxic, physiologically acceptable) salts. Salts ofthe compounds of Formula I may be formed, for example, by reacting acompound of Formula I with an amount of acid or base, such as anequivalent amount, in a medium such as one in which the saltprecipitates or in an aqueous medium followed by lyophilization.

Exemplary acid addition salts include acetates, ascorbates, benzoates,benzenesulfonates, bisulfates, borates, butyrates, citrates,camphorates, camphorsulfonates, fumarates, hydrochlorides,hydrobromides, hydroiodides, lactates, maleates, methanesulfonates,naphthalenesulfonates, nitrates, oxalates, phosphates, propionates,salicylates, succinates, sulfates, tartarates, thiocyanates,toluenesulfonates (also known as tosylates,) and the like. Additionally,acids which are generally considered suitable for the formation ofpharmaceutically useful salts from basic pharmaceutical compounds arediscussed, for example, by P. Stahl et al, Camille G. (eds.) Handbook ofPharmaceutical Salts. Properties, Selection and Use. (2002) Zurich:Wiley-VCH; S. Berge et al, Journal of Pharmaceutical Sciences (1977)66(1) 1-19; P. Gould, International J. of Pharmaceutics (1986) 33201-217; Anderson et al, The Practice of Medicinal Chemistry (1996),Academic Press, New York; and in The Orange Book (Food & DrugAdministration, Washington, D.C. on their website). These disclosuresare incorporated herein by reference.

Exemplary basic salts include ammonium salts, alkali metal salts such assodium, lithium, and potassium salts, alkaline earth metal salts such ascalcium and magnesium salts, salts with organic bases (for example,organic amines) such as dicyclohexylamines, t-butyl amines, and saltswith amino acids such as arginine, lysine and the like. Basicnitrogen-containing groups may be quarternized with agents such as loweralkyl halides (e.g., methyl, ethyl, and butyl chlorides, bromides andiodides), dialkyl sulfates (e.g., dimethyl, diethyl, and dibutylsulfates), long chain halides (e.g., decyl, lauryl, and stearylchlorides, bromides and iodides), aralkyl halides (e.g., benzyl andphenethyl bromides), and others.

Crystals

The Btk inhibitor compounds of the present invention may exist asamorphous forms or crystalline forms.

The compounds of Formula I may have the ability to crystallize in morethan one form, a characteristic known as polymorphism, and it isunderstood that such polymorphic forms (“polymorphs”) are within thescope of Formula I. Polymorphism generally can occur as a response tochanges in temperature or pressure or both and can also result fromvariations in the crystallization process. Polymorphs can bedistinguished by various physical characteristics known in the art suchas x-ray diffraction patterns, solubility and melting point.

Solvates

The compounds having Formula I or the pharmaceutically acceptable saltsmay form hydrates or solvates. It is known to those of skill in the artthat charged compounds form hydrated species when lyophilized withwater, or form solvated species when concentrated in a solution with anappropriate organic solvent. The compounds of this invention include thehydrates or solvates of the compounds listed.

One or more compounds of the invention having Formula I or thepharmaceutically acceptable salts or solvates thereof may exist inunsolvated as well as solvated forms with pharmaceutically acceptablesolvents such as water, ethanol, and the like, and it is intended thatthe invention embrace both solvated and unsolvated forms. “Solvate”means a physical association of a compound of this invention with one ormore solvent molecules. This physical association involves varyingdegrees of ionic and covalent bonding, including hydrogen bonding. Incertain instances the solvate will be capable of isolation, for examplewhen one or more solvent molecules are incorporated in the crystallattice of the crystalline solid. “Solvate” encompasses bothsolution-phase and isolatable solvates. Non-limiting examples ofsuitable solvates include ethanolates, methanolates, and the like.“Hydrate” is a solvate wherein the solvent molecule is H₂O.

Preparation of solvates is generally known. Thus, for example, M. Cairaet al, J. Pharmaceutical Sci., 93(3), 601-611 (2004) describe thepreparation of the solvates of the antifungal fluconazole in ethylacetate as well as from water. Similar preparations of solvates,hemisolvate, hydrates and the like are described by E. C. van Tonder etal, AAPS PharmSciTech., 5(1), article 12 (2004); and A. L. Bingham etal, Chem. Commun. 603-604 (2001). A typical, non-limiting, processinvolves dissolving the inventive compound in desired amounts of thedesired solvent (organic or water or mixtures thereof) at a higher thanambient temperature, and cooling the solution at a rate sufficient toform crystals which are then isolated by standard methods. Analyticaltechniques such as, for example IR spectroscopy, show the presence ofthe solvent (or water) in the crystals as a solvate (or hydrate).

Optical Isomers

The compounds of Formula I may contain asymmetric or chiral centers,and, therefore, exist in different stereoisomeric forms. It is intendedthat all stereoisomeric forms of the compounds of Formula I, as well asmixtures thereof, including racemic mixtures, form part of the presentinvention. In addition, the present invention embraces all geometric andpositional isomers. For example, if a compound of Formula I incorporatesa double bond or a fused ring, both the cis- and trans-forms, as well asmixtures, are embraced within the scope of the invention. Suchstereoisomeric forms also include enantiomers and diastereoisomers, etc.

For chiral compounds, methods for asymmetric synthesis whereby the purestereoisomers are obtained are well known in the art, e.g. synthesiswith chiral induction, synthesis starting from chiral intermediates,enantioselective enzymatic conversions, separation of stereoisomersusing chromatography on chiral media. Such methods are described inChirality in Industry (edited by A. N. Collins, G. N. Sheldrake and J.Crosby, 1992; John Wiley). Likewise methods for synthesis of geometricalisomers are also well known in the art.

Diastereomeric mixtures can be separated into their individualdiastereomers on the basis of their physical chemical differences bymethods well known to those skilled in the art, such as, for example, bychromatography and/or fractional crystallization. Enantiomers can beseparated by converting the enantiomeric mixture into a diastereomericmixture by reaction with an appropriate optically active compound (e.g.chiral auxiliary such as a chiral alcohol or Mosher's acid chloride),separating the diastereomers and converting (e.g. hydrolyzing) theindividual diastereomers to the corresponding pure enantiomers. Also,some of the compounds of Formula I may be atropisomers (e.g. substitutedbiaryls) and are considered as part of this invention. Enantiomers canalso be separated by use of chiral HPLC column.

It is also possible that the compounds of Formula I may exist indifferent tautomeric forms, and all such forms are embraced within thescope of the invention. Also, for example, all keto-enol andimine-enamine forms of the compounds are included in the invention.

All stereoisomers (for example, geometric isomers, optical isomers andthe like) of the present compounds (including those of the salts,solvates, esters and prodrugs of the compounds as well as the salts,solvates and esters of the prodrugs), such as those which may exist dueto asymmetric carbons on various substituents, including enantiomericforms (which may exist even in the absence of asymmetric carbons),rotameric forms, atropisomers, and diastereomeric forms, arecontemplated within the scope of this invention, as are positionalisomers. Individual stereoisomers of the compounds of the invention may,for example, be substantially free of other isomers, or may be admixed,for example, as racemates or with all other, or other selected,stereoisomers. The chiral centers of the present invention can have theS or R configuration as defined by the IUPAC 1974 Recommendations. Theuse of the terms “salt”, “solvate”, “ester”, “prodrug” and the like, isintended to equally apply to the salt, solvate, ester and prodrug ofenantiomers, stereoisomers, rotamers, tautomers, positional isomers,racemates or prodrugs of the inventive compounds.

Prodrugs

A discussion of prodrugs is provided in T. Higuchi and V. Stella,Pro-drugs as Novel Delivery Systems (1987) 14 of the A.C.S. SymposiumSeries, and in Bioreversible Carriers in Drug Design, (1987) Edward B.Roche, ed., American Pharmaceutical Association and Pergamon Press. Theterm “prodrug” means a compound (e.g, a drug precursor) that istransformed in vivo to yield a compound of Formula I or apharmaceutically acceptable salt, hydrate or solvate of the compound.The transformation may occur by various mechanisms (e.g. by metabolic orchemical processes), such as, for example, through hydrolysis in blood.A discussion of the use of prodrugs is provided by T. Higuchi and W.Stella, “Pro-drugs as Novel Delivery Systems,” Vol. 14 of the A.C.S.Symposium Series, and in Bioreversible Carriers in Drug Design, ed.Edward B. Roche, American Pharmaceutical Association and Pergamon Press,1987.

Isotopes

In the compounds of Formula I, the atoms may exhibit their naturalisotopic abundances, or one or more of the atoms may be artificiallyenriched in a particular isotope having the same atomic number, but anatomic mass or mass number different from the atomic mass or mass numberpredominantly found in nature. The present invention is meant to includeall suitable isotopic variations of the compounds of generic Formula I.For example, different isotopic forms of hydrogen (H) include protium(¹H) and deuterium (²H). Protium is the predominant hydrogen isotopefound in nature. Enriching for deuterium may afford certain therapeuticadvantages, such as increasing in vivo half-life or reducing dosagerequirements, or may provide a compound useful as a standard forcharacterization of biological samples.

Isotopically-enriched compounds within generic Formula I can be preparedwithout undue experimentation by conventional techniques well known tothose skilled in the art or by processes analogous to those described inthe Schemes and Examples herein using appropriate isotopically-enrichedreagents and/or intermediates.

Certain isotopically-labelled compounds of Formula I (e.g. those labeledwith ³H and ¹⁴C) are useful in compound and/or substrate tissuedistribution assays. Tritiated (i.e., ³H) and carbon-14 (i.e., ¹⁴C)isotopes are particularly preferred for their ease of preparation anddetectability. Further, substitution with heavier isotopes such asdeuterium (i.e., ²H) may afford certain therapeutic advantages resultingfrom greater metabolic stability (e.g., increased in vivo half-life orreduced dosage requirements) and hence may be preferred in somecircumstances. Isotopically labelled compounds of Formula I cangenerally be prepared by following procedures analogous to thosedisclosed in the Schemes and/or in the Examples hereinbelow, bysubstituting an appropriate isotopically labeled reagent for anon-isotopically labeled reagent.

Utilities

The compounds having Formula I and pharmaceutical compositions thereofcan be used to treat or prevent a variety of conditions, diseases ordisorders mediated by Bruton's Tyrosine kinase (Btk). Such Btk-mediatedconditions, diseases or disorders include, but are not limited to: (1)arthritis, including rheumatoid arthritis, juvenile arthritis, psoriaticarthritis and osteoarthritis; (2) asthma and other obstructive airwaysdiseases, including chronic asthma, late asthma, airwayhyper-responsiveness, bronchitis, bronchial asthma, allergic asthma,intrinsic asthma, extrinsic asthma, dust asthma, adult respiratorydistress syndrome, recurrent airway obstruction, and chronic obstructionpulmonary disease including emphysema; (3) autoimmune diseases ordisorders, including those designated as single organ or singlecell-type autoimmune disorders, for example Hashimoto's thyroiditis,autoimmune hemolytic anemia, autoimmune atrophic gastritis of perniciousanemia, autoimmune encephalomyelitis, autoimmune orchitis, Goodpasture'sdisease, autoimmune thrombocytopenia including idiopathic thrombopenicpurpura, sympathetic ophthalmia, myasthenia gravis, Graves' disease,primary biliary cirrhosis, chronic aggressive hepatitis, ulcerativecolitis and membranous glomerulopathy, those designated as involvingsystemic autoimmune disorder, for example systemic lupus erythematosis,immune thrombocytopenic purpura, rheumatoid arthritis, Sjogren'ssyndrome, Reiter's syndrome, polymyositis-dermatomyositis, systemicsclerosis, polyarteritis nodosa, multiple sclerosis and bullouspemphigoid, and additional autoimmune diseases, which can be B-cell(humoral) based or T-cell based, including Cogan's syndrome, ankylosingspondylitis, Wegener's granulomatosis, autoimmune alopecia, Type I orjuvenile onset diabetes, and thyroiditis; (4) cancers or tumors,including alimentary/gastrointestinal tract cancer, colon cancer, livercancer, skin cancer including mast cell tumor and squamous cellcarcinoma, breast and mammary cancer, ovarian cancer, prostate cancer,lymphoma and leukemia (including but not limited to acute myelogenousleukemia, chronic myelogenous leukemia, mantle cell lymphoma, NHL B celllymphomas (e.g. precursor B-ALL, marginal zone B cell lymphoma, chroniclymphocytic leukemia, diffuse large B cell lymphoma, Burkitt lymphoma,mediastinal large B-cell lymphoma), Hodgkin lymphoma, NK and T celllymphomas; TEL-Syk and ITK-Syk fusion driven tumors, myelomas includingmultiple myeloma, myeloproliferative disorders kidney cancer, lungcancer, muscle cancer, bone cancer, bladder cancer, brain cancer,melanoma including oral and metastatic melanoma, Kaposi's sarcoma,proliferative diabetic retinopathy, and angiogenic-associated disordersincluding solid tumors, and pancreatic cancer; (5) diabetes, includingType I diabetes and complications from diabetes; (6) eye diseases,disorders or conditions including autoimmune diseases of the eye,keratoconjunctivitis, vernal conjunctivitis, uveitis including uveitisassociated with Behcet's disease and lens-induced uveitis, keratitis,herpetic keratitis, conical keratitis, corneal epithelial dystrophy,keratoleukoma, ocular premphigus, Mooren's ulcer, scleritis, Grave'sophthalmopathy, Vogt-Koyanagi-Harada syndrome, keratoconjunctivitissicca (dry eye), phlyctenule, iridocyclitis, sarcoidosis, endocrineophthalmopathy, sympathetic ophthalmitis, allergic conjunctivitis, andocular neovascularization; (7) intestinal inflammations, allergies orconditions including Crohn's disease and/or ulcerative colitis,inflammatory bowel disease, coeliac diseases, proctitis, eosinophilicgastroenteritis, and mastocytosis; (8) neurodegenerative diseasesincluding motor neuron disease, Alzheimer's disease, Parkinson'sdisease, amyotrophic lateral sclerosis, Huntington's disease, cerebralischemia, or neurodegenerative disease caused by traumatic injury,strike, glutamate neurotoxicity or hypoxia; ischemic/reperfusion injuryin stroke, myocardial ischemica, renal ischemia, heart attacks, cardiachypertrophy, atherosclerosis and arteriosclerosis, organ hypoxia; (9)platelet aggregation and diseases associated with or caused by plateletactivation, such as arteriosclerosis, thrombosis, intimal hyperplasiaand restenosis following vascular injury; (10) conditions associatedwith cardiovascular diseases, including restenosis, acute coronarysyndrome, myocardial infarction, unstable angina, refractory angina,occlusive coronary thrombus occurring post-thrombolytic therapy orpost-coronary angioplasty, a thrombotically mediated cerebrovascularsyndrome, embolic stroke, thrombotic stroke, transient ischemic attacks,venous thrombosis, deep venous thrombosis, pulmonary embolus,coagulopathy, disseminated intravascular coagulation, thromboticthrombocytopenic purpura, thromboangiitis obliterans, thrombotic diseaseassociated with heparin-induced thrombocytopenia, thromboticcomplications associated with extracorporeal circulation, thromboticcomplications associated with instrumentation such as cardiac or otherintravascular catheterization, intra-aortic balloon pump, coronary stentor cardiac valve, conditions requiring the fitting of prostheticdevices, and the like; (11) skin diseases, conditions or disordersincluding atopic dermatitis, eczema, psoriasis, scleroderma, pruritusand other pruritic conditions; (12) allergic reactions includinganaphylaxis, allergic rhinitis, allergic dermatitis, allergic urticaria,angioedema, allergic asthma, or allergic reaction to insect bites, food,drugs, or pollen; (13) transplant rejection, including pancreas islettransplant rejection, bone marrow transplant rejection,graft-versus-host disease, organ and cell transplant rejection such asbone marrow, cartilage, cornea, heart, intervertebral disc, islet,kidney, limb, liver, lung, muscle, myoblast, nerve, pancreas, skin,small intestine, or trachea, and xeno transplantation; and (14) lowgrade scarring including scleroderma, increased fibrosis, keloids,post-surgical scars, pulmonary fibrosis, vascular spasms, migraine,reperfusion injury, and post-myocardial infarction.

The invention thus provides compounds of Formula I and salts thereof foruse in therapy, and particularly in the treatment of disorders, diseasesand conditions mediated by inappropriate Btk activity.

The inappropriate Btk activity referred to herein is any Btk activitythat deviates from the normal Btk activity expected in a particularmammalian subject. Inappropriate Btk activity may take the form of, forinstance, an abnormal increase in activity, or an aberration in thetiming and or control of Btk activity. Such inappropriate activity mayresult then, for example, from overexpression or mutation of the proteinkinase leading to inappropriate or uncontrolled activation.

In one embodiment, the present invention provides for the use of acompound of Formula I, or a pharmaceutically acceptable salt thereof forthe manufacture of a medicament for the treatment of a Btk-mediateddisorder.

In another embodiment, the present invention provides methods ofregulating, modulating, or inhibiting Btk for the prevention and/ortreatment of disorders related to unregulated or inappropriate Btkactivity.

In a further embodiment, the present invention provides a method fortreating a subject suffering from a disorder mediated by Btk, whichcomprises administering to said subject a compound of Formula I or apharmaceutically acceptable salt thereof in an amount effective to treatthe Btk-mediated disorder.

A further aspect of the invention resides in the use of a compound ofFormula I or a pharmaceutically acceptable salt thereof for themanufacture of a medicament to be used for the treatment of chronic Bcell disorders in which T cells play a prominent role.

Thus, the compounds according to the invention may be used in therapiesto treat or prevent Bruton's Tyrosine Kinase (Btk) mediated diseases,conditions and disorders. Btk mediated diseases, conditions anddisorders as used herein, mean any disease, condition or disorder inwhich B cells, mast cells, myeloid cells or osteoclasts play a centralrole. These diseases include but are not limited to, immune, autoimmuneand inflammatory diseases, allergies, infectious diseases, boneresorption disorders and proliferative diseases.

Immune, autoimmune and inflammatory diseases that may be treated orprevented with the compounds of the present invention include rheumaticdiseases (e.g. rheumatoid arthritis, psoriatic arthritis, infectiousarthritis, progressive chronic arthritis, deforming arthritis,osteoarthritis, traumatic arthritis, gouty arthritis, Reiter's syndrome,polychondritis, acute synovitis and spondylitis), glomerulonephritis(with or without nephrotic syndrome), Goodpasture's syndrome, (andassociated glomerulonephritis and pulmonary hemorrhage),atherosclerosis, autoimmune hematologic disorders (e.g. hemolyticanemia, aplasic anemia, idiopathic thrombocytopenia, chronic idiopathicthrombocytopenic purpura (ITP), and neutropenia), autoimmune gastritis,and autoimmune inflammatory bowel diseases (e.g. ulcerative colitis andCrohn's disease), irritable bowel syndrome, host versus graft disease,allograft rejection, chronic thyroiditis, Graves' disease, Sjorgren'sdisease, scleroderma, diabetes (type I and type II), active hepatitis(acute and chronic), pancreatitis, primary billiary cirrhosis,myasthenia gravis, multiple sclerosis, systemic lupus erythematosis,psoriasis, atopic dermatitis, dermatomyositis, contact dermatitis,eczema, skin sunburns, vasculitis (e.g. Behcet's disease),ANCA-associated and other vasculitudes, chronic renal insufficiency,Stevens-Johnson syndrome, inflammatory pain, idiopathic sprue, cachexia,sarcoidosis, Guillain-Barré syndrome, uveitis, conjunctivitis, keratoconjunctivitis, otitis media, periodontal disease, Addison's disease,Parkinson's disease, Alzheimer's disease, diabetes, septic shock,myasthenia gravis, pulmonary interstitial fibrosis, asthma, bronchitis,rhinitis, sinusitis, pneumoconiosis, pulmonary insufficiency syndrome,pulmonary emphysema, pulmonary fibrosis, silicosis, chronic inflammatorypulmonary disease (e.g. chronic obstructive pulmonary disease) and otherinflammatory or obstructive disease on airways.

Allergies that may be treated or prevented include, among others,allergies to foods, food additives, insect poisons, dust mites, pollen,animal materials and contact allergens, type I hypersensitivity allergicasthma, allergic rhinitis, allergic conjunctivitis.

Infectious diseases that may be treated or prevented include, amongothers, sepsis, septic shock, endotoxic shock, sepsis by Gram-negativebacteria, shigellosis, meningitis, cerebral malaria, pneumonia,tuberculosis, viral myocarditis, viral hepatitis (hepatitis A, hepatitisB and hepatitis C), HIV infection, retinitis caused by cytomegalovirus,influenza, herpes, treatment of infections associated with severe burns,myalgias caused by infections, cachexia secondary to infections, andveterinary viral infections such as lentivirus, caprine arthritic virus,visna-maedi virus, feline immunodeficiency virus, bovineimmunodeficiency virus or canine immunodeficiency virus.

Bone resorption disorders that may be treated or prevented include,among others, osteoporosis, osteoarthritis, traumatic arthritis, goutyarthritis and bone disorders related with multiple myeloma.

Proliferative diseases that may be treated or prevented include, amongothers, non-Hodgkin lymphoma (in particular the subtypes diffuse largeB-cell lymphoma (DLBCL) and mantle cell lymphoma (MCL)), B cell chroniclymphocytic leukemia and acute lymphoblastic leukemia (ALL) with matureB cell, ALL in particular.

In particular the compounds of Formula I or pharmaceutically acceptablesalts may be used for the treatment of B cell lymphomas resulting fromchronic active B cell receptor signaling.

Yet another aspect of the present invention provides a method fortreating diseases caused by or associated with Fc receptor signalingcascades, including FceRI and/or FcgRI-mediated degranulation as atherapeutic approach towards the treatment or prevention of diseasescharacterized by, caused by and/or associated with the release orsynthesis of chemical mediators of such Fc receptor signaling cascadesor degranulation. In addition, Btk is known to play a critical role inimmunotyrosine-based activation motif (ITAM) signaling, B cell receptorsignaling, T cell receptor signaling and is an essential component ofintegrin beta (1), beta (2), and beta (3) signaling in neutrophils.Thus, compounds of the present invention can be used to regulate Fcreceptor, ITAM, B cell receptor and integrin signaling cascades, as wellas the cellular responses elicited through these signaling cascades.Non-limiting examples of cellular responses that may be regulated orinhibited include respiratory burst, cellular adhesion, cellulardegranulation, cell spreading, cell migration, phagocytosis, calcium ionflux, platelet aggregation and cell maturation.

Combination Therapy

Included herein are methods of treatment and/or pharmaceuticalcompositions in which at least one compound of Formula I or apharmaceutically acceptable salt thereof is administered in combinationwith at least one other active agent. The other active agent is ananti-inflammatory agent, an immunosuppressant agent, or achemotherapeutic agent. Anti-inflammatory agents include but are notlimited to NSAIDs, non-specific and COX-2 specific cyclooxygenase enzymeinhibitors, gold compounds, corticosteroids, methotrexate, tumornecrosis factor receptor (TNF) receptors antagonists, immunosuppressantsand methotrexate.

Examples of NSAIDs include, but are not limited to, ibuprofen,flurbiprofen, naproxen and naproxen sodium, diclofenac, combinations ofdiclofenac sodium and misoprostol, sulindac, oxaprozin, diflunisal,piroxicam, indomethacin, etodolac, fenoprofen calcium, ketoprofen,sodium nabumetone, sulfasalazine, tolmetin sodium, andhydroxychloroquine. Examples of NSAIDs also include COX-2 specificinhibitors such as celecoxib, valdecoxib, lumiracoxib and/or etoricoxib.

In some embodiments, the anti-inflammatory agent is a salicylate.Salicylates include by are not limited to acetylsalicylic acid oraspirin, sodium salicylate, and choline and magnesium salicylates.

The anti-inflammatory agent may also be a corticosteroid. For example,the corticosteroid may be cortisone, dexamethasone, methylprednisolone,prednisolone, prednisolone sodium phosphate, or prednisone.

In additional embodiments the anti-inflammatory agent is a gold compoundsuch as gold sodium thiomalate or auranofin.

The invention also includes embodiments in which the anti-inflammatoryagent is a metabolic inhibitor such as a dihydrofolate reductaseinhibitor, such as methotrexate or a dihydroorotate dehydrogenaseinhibitor, such as leflunomide.

Other embodiments of the invention pertain to combinations in which atleast one anti-inflammatory agent is an anti-C5 monoclonal antibody(such as eculizumab or pexelizumab), a TNF antagonist, such asetanercept, or infliximab, which is an anti-TNF alpha monoclonalantibody.

Still other embodiments of the invention pertain to combinations inwhich at least one active agent is an immunosuppressant agent, such asan immunosuppressant compound chosen from methotrexate, leflunomide,cyclosporine, tacrolimus, azathioprine, and mycophenolate mofetil.

B-cells and B-cell precursors expressing BTK have been implicated in thepathology of B-cell malignancies, including, but not limited to, B-celllymphoma, lymphoma (including Hodgkin's and non-Hodgkin's lymphoma),hairy cell lymphoma, multiple myeloma, chronic and acute myelogenousleukemia and chronic and acute lymphocytic leukemia.

BTK has been shown to be an inhibitor of the Fas/APO-1 (CD-95) deathinducing signaling complex (DISC) in B-lineage lymphoid cells. The fateof leukemia/lymphoma cells may reside in the balance between theopposing proapoptotic effects of caspases activated by DISC and anupstream anti-apoptotic regulatory mechanism involving BTK and/or itssubstrates (Vassilev et al., J. Biol. Chem. 1998, 274, 1646-1656).

It has also been discovered that BTK inhibitors are useful aschemosensitizing agents, and, thus, are useful in combination with otherchemotherapeutic agents, in particular, drugs that induce apoptosis.Examples of other chemotherapeutic agents that can be used incombination with chemosensitizing BTK inhibitors include topoisomerase Iinhibitors (camptothecin or topotecan), topoisomerase II inhibitors(e.g. daunomycin and etoposide), alkylating agents (e.g.cyclophosphamide, melphalan and BCNU), tubulin directed agents (e.g.taxol and vinblastine), and biological agents (e.g. antibodies such asanti CD20 antibody, IDEC 8, immunotoxins, and cytokines).

Btk activity has also been associated with some leukemias expressing thebcr-abl fusion gene resulting from translocation of parts of chromosome9 and 22. This abnormality is commonly observed in chronic myelogenousleukemia. Btk is constitutively phosphorylated by the bcr-abl kinasewhich initiates downstream survival signals which circumvents apoptosisin bcr-abl cells. (N. Feldhahn et al. J. Exp. Med. 2005201(11):1837-1852).

The compound(s) of Formula I and the other pharmaceutically activeagent(s) may be administered together or separately and, whenadministered separately this may occur simultaneously or sequentially inany order. The amounts of the compound(s) of Formula I and the otherpharmaceutically active agent(s) and the relative timings ofadministration will be selected in order to achieve the desired combinedtherapeutic effect.

For the treatment of the inflammatory diseases, rheumatoid arthritis,psoriasis, inflammatory bowel disease, COPD, asthma and allergicrhinitis a compound of Formula I may be combined with one or more otheractive agents such as: (1) TNF-α inhibitors such as infliximab(Remicade®), etanercept (Enbrel®), adalimumab (Humira®), certolizumabpegol (Cimzia®), and golimumab (Simponi®); (2) non-selective COX-I/COX-2inhibitors (such as piroxicam, diclofenac, propionic acids such asnaproxen, flubiprofen, fenoprofen, ketoprofen and ibuprofen, fenamatessuch as mefenamic acid, indomethacin, sulindac, etodolac, azapropazone,pyrazolones such as phenylbutazone, salicylates such as aspirin); (3)COX-2 inhibitors (such as meloxicam, celecoxib, rofecoxib, valdecoxiband etoricoxib); (4) other agents for treatment of rheumatoid arthritisincluding methotrexate, leflunomide, sulfasalazine, azathioprine,cyclosporin, tacrolimus, penicillamine, bucillamine, actarit,mizoribine, lobenzarit, ciclesonide, hydroxychloroquine,d-penicillamine, aurothiomalate, auranofin or parenteral or oral gold,cyclophosphamide, Lymphostat-B, BAFF/APRIL inhibitors and CTLA-4-Ig ormimetics thereof; (5) leukotriene biosynthesis inhibitor, 5-lipoxygenase(5-LO) inhibitor or 5-lipoxygenase activating protein (FLAP) antagonistsuch as zileuton; (6) LTD4 receptor antagonist such as zafirlukast,montelukast and pranlukast; (7) PDE4 inhibitor such as roflumilast,cilomilast, AWD-12-281 (Elbion), and PD-168787 (Pfizer); (8)antihistaminic H1 receptor antagonists such as cetirizine,levocetirizine, loratadine, desloratadine, fexofenadine, astemizole,azelastine, levocabastine, olopatidine, methapyrilene andchlorpheniramine; (9) α1- and α2-adrenoceptor agonist vasoconstrictorsympathomimetic agent, such as propylhexedrine, phenylephrine,phenylpropanolamine, pseudoephedrine, naphazoline hydrochloride,oxymetazoline hydrochloride, tetrahydrozoline hydrochloride,xylometazoline hydrochloride, and ethylnorepinephrine hydrochloride;(10) anticholinergic agents such as ipratropium bromide, tiotropiumbromide, oxitropium bromide, aclindinium bromide, glycopyrrolate,(R,R)-glycopyrrolate, pirenzepine, and telenzepine; (11) β-adrenoceptoragonists such as metaproterenol, isoproterenol, isoprenaline, albuterol,formoterol (particularly the fumarate salt), salmeterol (particularlythe xinafoate salt), terbutaline, orciprenaline, bitolterol mesylate,fenoterol, and pirbuterol, or methylxanthanines including theophyllineand aminophylline, sodium cromoglycate; (12) insulin-like growth factortype I (IGF-1) mimetic; (13) glucocorticosteroids, especially inhaledglucocorticoid with reduced systemic side effects, such as prednisone,prednisolone, flunisolide, triamcinolone acetonide, beclomethasonedipropionate, budesonide, fluticasone propionate, ciclesonide andmometasone furoate; (14) kinase inhibitors such as inhibitors of theJanus Kinases (JAK 1 and/or JAK2 and/or JAK 3 and/or TYK2), p38 MAPK andIKK2; (15) B-cell targeting biologics such as rituximab (Rituxan®); (16)selective costimulation modulators such as abatacept (Orencia); (17)interleukin inhibitors, such as IL-1 inhibitor anakinra (Kineret) andIL-6 inhibitor tocilizumab (Actemra).

The present invention also provides for “triple combination” therapy,comprising a compound of Formula I or a pharmaceutically acceptable saltthereof together with beta2-adrenoreceptor agonist and ananti-inflammatory corticosteroid. Preferably this combination is fortreatment and/or prophylaxis of asthma, COPD or allergic rhinitis. Thebeta2-adrenoreceptor agonist and/or the anti-inflammatory corticosteroidcan be as described above and/or as described in WO 03/030939 A1.Representative examples of such a “triple” combination are a compound ofFormula I or a pharmaceutically acceptable salt thereof in combinationwith the components of Advair® (salmeterol xinafoate and fluticasonepropionate), Symbicort® (budesonide and formoterol fumarate), or Dulera®(mometasone furoate and formoterol).

For the treatment of cancer a compound of Formula I may be combined withone or more of an anticancer agents. Examples of such agents can befound in Cancer Principles and Practice of Oncology by V. T. Devita andS. Hellman (editors), 6^(th) edition (Feb. 15, 2001), LippincottWilliams & Wilkins Publishers. A person of ordinary skill in the artwould be able to discern which combinations of agents would be usefulbased on the particular characteristics of the drugs and the cancerinvolved. Such anti-cancer agents include, but are not limited to, thefollowing: (1) estrogen receptor modulator such as diethylstibestral,tamoxifen, raloxifene, idoxifene, LY353381, LY117081, toremifene,fluoxymestero, and SH646; (2) other hormonal agents including aromataseinhibitors (e.g., aminoglutethimide, tetrazole anastrozole, letrozoleand exemestane), luteinizing hormone release hormone (LHRH) analogues,ketoconazole, goserelin acetate, leuprolide, megestrol acetate andmifepristone; (3) androgen receptor modulator such as finasteride andother 5α-reductase inhibitors, nilutamide, flutamide, bicalutamide,liarozole, and abiraterone acetate; (4) retinoid receptor modulator suchas bexarotene, tretinoin, 13-cis-retinoic acid, 9-cis-retinoic acid,α-difluoromethylornithine, ILX23-7553, trans-N-(4′-hydroxyphenyl)retinamide, and N-4-carboxyphenyl retinamide; (5) antiproliferativeagent such as antisense RNA and DNA oligonucleotides such as G3139,ODN698, RVASKRAS, GEM231, and INX3001, and antimetabolites such asenocitabine, carmofur, tegafur, pentostatin, doxifluridine,trimetrexate, fludarabine, capecitabine, galocitabine, cytarabineocfosfate, fosteabine sodium hydrate, raltitrexed, paltitrexid,emitefur, tiazofurin, decitabine, nolatrexed, pemetrexed, nelzarabine,2′-deoxy-2′-methylidenecytidine, 2′-fluoromethylene-2′-deoxycytidine,N6-[4-deoxy-4-[N2-[2(E),4(E)-tetradecadienoyl]glycylamino]-L-glycero-B-L-manno-heptopyranosyl]adenine,aplidine, ecteinascidin, troxacitabine, aminopterin, 5-flurouracil,floxuridine, methotrexate, leucovarin, hydroxyurea, thioguanine (6-TG),mercaptopurine (6-MP), cytarabine, pentostatin, fludarabine phosphate,cladribine (2-CDA), asparaginase, gemcitabine, alanosine, swainsonine,lometrexol, dexrazoxane, methioninase, and3-aminopyridine-2-carboxaldehyde thiosemicarbazone; (6) prenyl-proteintransferase inhibitor including farnesyl-protein transferase (FPTase),geranylgeranyl-protein transferase type I (GGPTase-I), andgeranylgeranyl-protein transferase type-II (GGPTase-II, also called RabGGPTase); (7) HMG-CoA reductase inhibitor such as lovastatin,simvastatin, pravastatin, atorvastatin, fluvastatin and rosuvastatin;(8) angiogenesis inhibitor such as inhibitors of the tyrosine kinasereceptors Flt-1 (VEGFR1) and Flk-1/KDR (VEGFR2), inhibitors ofepidermal-derived, fibroblast-derived, or platelet derived growthfactors, MMP (matrix metalloprotease) inhibitors, integrin blockers,interferon-α, interleukin-12, erythropoietin (epoietin-α),granulocyte-CSF (filgrastin), granulocyte, macrophage-CSF(sargramostim), pentosan polysulfate, cyclooxygenase inhibitors,steroidal anti-inflammatories, carboxyamidotriazole, combretastatin A-4,squalamine, 6-O-chloroacetyl-carbonyl)-fumagillol, thalidomide,angiostatin, troponin-1, angiotensin II antagonists, heparin,carboxypeptidase U inhibitors, and antibodies to VEGF, endostatin,ukrain, ranpimase, IM862, acetyldinanaline,5-amino-1-[[3,5-dichloro-4-(4-chlorobenzoyl)phenyl]methyl]-1H-1,2,3-triazole-4-carboxamide,CM101, squalamine, combretastatin, RPI4610, NX31838, sulfatedmannopentaose phosphate, and3-[(2,4-dimethylpyrrol-5-yl)methylene]-2-indolinone (SU5416); (9) PPAR-γagonists, PPAR-6 agonists, thiazolidinediones (such as DRF2725, CS-011,troglitazone, rosiglitazone, and pioglitazone), fenofibrate,gemfibrozil, clofibrate, GW2570, SB219994, AR-H039242, JTT-501, MCC-555,GW2331, GW409544, NN2344, KRP297, NP0110, DRF4158, NN622, G1262570,PNU182716, DRF552926,2-[(5,7-dipropyl-3-trifluoromethyl-1,2-benzisoxazol-6-yl)oxy]-2-methylpropionicacid (disclosed in U.S. Ser. No. 09/782,856), and(2R)-7-(3-(2-chloro-4-(4-fluorophenoxy)phenoxy)propoxy)-2-ethylchromane-2-carboxylicacid (disclosed in U.S. Ser. No. 60/235,708 and 60/244,697); (9)inhibitor of inherent multidrug resistance including inhibitors ofp-glycoprotein (P-gp), such as LY335979, XR9576, OC144-093, R101922,VX853 and PSC833 (valspodar); (10) inhibitor of cell proliferation andsurvival signaling such as inhibitors of EGFR (for example gefitinib anderlotinib), inhibitors of ERB-2 (for example trastuzumab), inhibitors ofIGF1R such as MK-0646 (dalotuzumab), inhibitors of CD20 (rituximab),inhibitors of cytokine receptors, inhibitors of MET, inhibitors of PI3Kfamily kinase (for example LY294002), serine/threonine kinases(including but not limited to inhibitors of Akt such as described in (WO03/086404, WO 03/086403, WO 03/086394, WO 03/086279, WO 02/083675, WO02/083139, WO 02/083140 and WO 02/083138), inhibitors of Raf kinase (forexample BAY-43-9006), inhibitors of MEK (for example CI-1040 andPD-098059) and inhibitors of mTOR (for example Wyeth CCI-779 and AriadAP23573); (11) a bisphosphonate such as etidronate, pamidronate,alendronate, risedronate, zoledronate, ibandronate, incadronate orcimadronate, clodronate, EB-1053, minodronate, neridronate, piridronateand tiludronate; (12) γ-secretase inhibitors, (13) agents that interferewith receptor tyrosine kinases (RTKs) including inhibitors of c-Kit,Eph, PDGF, Flt3 and c-Met; (14) agent that interferes with a cell cyclecheckpoint including inhibitors of ATR, ATM, the Chk1 and Chk2 kinasesand cdk and cdc kinase inhibitors and are specifically exemplified by7-hydroxystaurosporin, flavopiridol, CYC202 (Cyclacel) and BMS-387032;(15) BTK inhibitors such as PC132765, AVL-292 and AVL-101; (16) PARPinhibitors including iniparib, olaparib, AGO14699, ABT888 and MK4827;(16) ERK inhibitors; (17) mTOR inhibitors such as sirolimus,ridaforolimus, temsirolimus, everolimus; (18) cytotoxic/cytostaticagents.

“Cytotoxic/cytostatic agents” refer to compounds which cause cell deathor inhibit cell proliferation primarily by interfering directly with thecell's functioning or inhibit or interfere with cell mytosis, includingalkylating agents, tumor necrosis factors, intercalators, hypoxiaactivatable compounds, microtubule inhibitors/microtubule-stabilizingagents, inhibitors of mitotic kinesins, inhibitors of histonedeacetylase, inhibitors of kinases involved in mitotic progression,antimetabolites; biological response modifiers; hormonal/anti-hormonaltherapeutic agents, haematopoietic growth factors, monoclonal antibodytargeted therapeutic agents, topoisomerase inhibitors, proteasomeinhibitors and ubiquitin ligase inhibitors.

Examples of cytotoxic agents include, but are not limited to, sertenef,cachectin, chlorambucil, cyclophosphamide, ifosfamide, mechlorethamine,melphalan, uracil mustard, thiotepa, busulfan, carmustine, lomustine,streptozocin, tasonermin, lonidamine, carboplatin, altretamine,dacarbazine, procarbazine, prednimustine, dibromodulcitol, ranimustine,fotemustine, nedaplatin, oxaliplatin, temozolomide, heptaplatin,estramustine, improsulfan tosilate, trofosfamide, nimustine,dibrospidium chloride, pumitepa, lobaplatin, satraplatin, profiromycin,cisplatin, irofulven, dexifosfamide,cis-aminedichloro(2-methyl-pyridine)platinum, benzylguanine,glufosfamide, GPX100, (trans, trans,trans)-bis-mu-(hexane-1,6-diamine)-mu-[diamine-platinum(II)]bis[diamine(chloro)platinum(II)]tetrachloride, diarizidinylspermine, arsenic trioxide,1-(11-dodecylamino-10-hydroxyundecyl)-3,7-dimethylxanthine, zorubicin,doxorubicin, daunorubicin, idarubicin, anthracenedione, bleomycin,mitomycin C, dactinomycin, plicatomycin, bisantrene, mitoxantrone,pirarubicin, pinafide, valrubicin, amrubicin, antineoplaston,3′-deamino-3′-morpholino-13-deoxo-10-hydroxycarminomycin, annamycin,galarubicin, elinafide, MEN10755, and4-demethoxy-3-deamino-3-aziridinyl-4-methylsulphonyl-daunorubicin.

An example of a hypoxia activatable compound is tirapazamine.

Examples of proteasome inhibitors include but are not limited tolactacystin and bortezomib.

Examples of microtubule inhibitors/microtubule-stabilising agentsinclude vincristine, vinblastine, vindesine, vinzolidine, vinorelbine,vindesine sulfate, 3′,4′-didehydro-4′-deoxy-8′-norvincaleukoblastine,podophyllotoxins (e.g., etoposide (VP-16) and teniposide (VM-26)),paclitaxel, docetaxol, rhizoxin, dolastatin, mivobulin isethionate,auristatin, cemadotin, RPR109881, BMS184476, vinflunine, cryptophycin,anhydrovinblastine,N,N-dimethyl-L-valyl-L-valyl-N-methyl-L-valyl-L-prolyl-L-proline-t-butylamide,TDX258, the epothilones (see for example U.S. Pat. Nos. 6,284,781 and6,288,237) and BMS188797.

Some examples of topoisomerase inhibitors are topotecan, hycaptamine,irinotecan, rubitecan,6-ethoxypropionyl-3′,4′-O-exo-benzylidene-chartreusin, lurtotecan,7-[2-(N-isopropylamino)ethyl]-(20S)camptothecin, BNP1350, BNPI1100,BN80915, BN80942, etoposide phosphate, teniposide, sobuzoxane,2′-dimethylamino-2′-deoxy-etoposide, GL331,N-[2-(dimethylamino)ethyl]-9-hydroxy-5,6-dimethyl-6H-pyrido[4,3-b]carbazole-1-carboxamide,asulacrine,2,3-(methylenedioxy)-5-methyl-7-hydroxy-8-methoxybenzo[c]-phenanthridinium,5-(3-aminopropylamino)-7,10-dihydroxy-2-(2-hydroxyethylaminomethyl)-6H-pyrazolo[4,5,1-de]acridin-6-one,N-[1-[2-(diethylamino)ethylamino]-7-methoxy-9-oxo-9H-thioxanthen-4-ylmethyl]formamide,N-(2-(dimethylamino)ethyl)acridine-4-carboxamide,6-[[2-(dimethylamino)ethyl]amino]-3-hydroxy-7H-indeno[2,1-c]quinolin-7-one,and dimesna.

Examples of inhibitors of mitotic kinesins include, but are not limitedto inhibitors of KSP, inhibitors of MKLP1, inhibitors of CENP-E,inhibitors of MCAK, inhibitors of Kifl4, inhibitors of Mphosph1 andinhibitors of Rab6-KIFL.

Examples of “histone deacetylase inhibitors” include, but are notlimited to, vorinostat, trichostatin A, oxamflatin, PXD101, MG98,valproic acid and scriptaid.

“Inhibitors of kinases involved in mitotic progression” include, but arenot limited to, inhibitors of aurora kinase, inhibitors of Polo-likekinases (PLK; in particular inhibitors of PLK-1), inhibitors of bub-1and inhibitors of bub-R1. An example of an “aurora kinase inhibitor” isVX-680.

“Antiproliferative agents” includes antisense RNA and DNAoligonucleotides such as G3139, ODN698, RVASKRAS, GEM231, and INX3001,and antimetabolites such as enocitabine, carmofur, tegafur, pentostatin,doxifluridine, trimetrexate, fludarabine, capecitabine, galocitabine,cytarabine ocfosfate, fosteabine sodium hydrate, raltitrexed,paltitrexid, emitefur, tiazofurin, decitabine, nolatrexed, pemetrexed,nelzarabine, 2′-deoxy-2′-methylidenecytidine,2′-fluoromethylene-2′-deoxycytidine,N6-[4-deoxy-4-[N2-[2,4-tetradecadienoyl]glycylamino]-L-glycero-B-L-manno-heptopyranosyl]adenine,aplidine, ecteinascidin, troxacitabine, aminopterin, 5-flurouracil,floxuridine, methotrexate, leucovarin, hydroxyurea, thioguanine (6-TG),mercaptopurine (6-MP), cytarabine, pentostatin, fludarabine phosphate,cladribine (2-CDA), asparaginase, gemcitabine, alanosine, swainsonine,lometrexol, dexrazoxane, methioninase, and3-aminopyridine-2-carboxaldehyde thiosemicarbazone.

Non-limiting examples of suitable agents used in cancer therapy that maybe combined with compounds of Formula I include, but are not limited to,abarelix; aldesleukin; alemtuzumab; alitretinoin; allopurinol;altretamine; amifostine; anastrozole; arsenic trioxide; asparaginase;azacitidine; bendamustine; bevacuzimab; bexarotene; bleomycin;bortezomib; busulfan; calusterone; capecitabine; carboplatin;carmustine; cetuximab; chlorambucil; cisplatin; cladribine; clofarabine;cyclophosphamide; cytarabine; dacarbazine; dactinomycin, actinomycin D;dalteparin; darbepoetin alfa; dasatinib; daunorubicin; degarelix;denileukin diftitox; dexrazoxane; docetaxel; doxorubicin; dromostanolonepropionate; eculizumab; Elliott's B Solution; eltrombopag; epirubicin;epoetin alfa; erlotinib; estramustine; etoposide phosphate; etoposide;everolimus; exemestane; filgrastim; floxuridine; fludarabine;fluorouracil; fulvestrant; gefitinib; gemcitabine; gemtuzumabozogamicin; goserelin acetate; histrelin acetate; hydroxyurea;ibritumomab tiuxetan; idarubicin; ifosfamide; imatinib mesylate;interferon alfa 2a; interferon alfa-2b; irinotecan; ixabepilone;lapatinib; lenalidomide; letrozole; leucovorin; leuprolide acetate;levamisole; lomustine; meclorethamine, nitrogen mustard; megestrolacetate; melphalan, L-PAM; mercaptopurine; mesna; methotrexate;methoxsalen; mitomycin C; mitotane; mitoxantrone; nandrolonephenpropionate; nelarabine; nilotinib; Nofetumomab; ofatumumab;oprelvekin; oxaliplatin; paclitaxel; palifermin; pamidronat;panitumumab; pazopanib; pegademase; pegaspargase; Pegfilgrastim;pemetrexed disodium; pentostatin; pipobroman; plerixafor; plicamycin,mithramycin); porfimer sodium; pralatrexate; procarbazine; quinacrine;Rasburicase; raloxifene hydrochloride; Rituximab; romidepsin;romiplostim; sargramostim; sargramostim; satraplatin; sorafenib;streptozocin; sunitinib maleate; tamoxifen; temozolomide; temsirolimus;teniposide; testolactone; thioguanine; thiotepa; topotecan; toremifene;tositumomab; trastuzumab; tretinoin; uracil mustard; valrubicin;vinblastine; vincristine; vinorelbine; vorinostat; and zoledronate.

It will be clear to a person skilled in the art that, where appropriate,the other therapeutic ingredient(s) may be used in the form of salts,for example as alkali metal or amine salts or as acid addition salts, orprodrugs, or as esters, for example lower alkyl esters, or as solvates,for example hydrates, to optimise the activity and/or stability and/orphysical characteristics, such as solubility, of the therapeuticingredient. It will be clear also that, where appropriate, thetherapeutic ingredients may be used in optically pure form.

The combinations referred to above may conveniently be presented for usein the form of a pharmaceutical composition and thus pharmaceuticalcompositions comprising a combination as defined above together with apharmaceutically acceptable diluent, carrier or excipient represent afurther aspect of the invention. These combinations are of particularinterest in respiratory diseases and are conveniently adapted forinhaled or intranasal delivery.

The individual compounds of such combinations may be administered eithersequentially or simultaneously in separate or combined pharmaceuticalcompositions. Preferably, the individual compounds will be administeredsimultaneously in a combined pharmaceutical composition. Appropriatedoses of known therapeutic agents will be readily appreciated by thoseskilled in the art.

Pharmaceutical Compositions

While it is possible that, for use in therapy, a compound of Formula I,as well as salts, solvates and physiological functional derivativesthereof, may be administered as the raw chemical, it is possible topresent the active ingredient as a pharmaceutical composition.Accordingly, the invention further provides a pharmaceutical compositionwhich comprises a compound of Formula I and salts, solvates andphysiological functional derivatives thereof, and one or morepharmaceutically acceptable carriers, diluents, or excipients. Thecompounds of the Formula I and salts, solvates and physiologicalfunctional derivatives thereof, are as described above. The carrier(s),diluent(s) or excipient(s) must be acceptable in the sense of beingcompatible with the other ingredients of the formulation and notdeleterious to the recipient thereof. In accordance with another aspectof the invention there is also provided a process for the preparation ofa pharmaceutical composition including admixing a compound of theFormula I, or salts, solvates and physiological functional derivativesthereof, with one or more pharmaceutically acceptable carriers, diluentsor excipients.

Routes of Administration

Pharmaceutical compositions of the present invention may be presented inunit dose forms containing a predetermined amount of active ingredientper unit dose. Such a unit may contain, for example, 5 μg to 1 μg,preferably 1 mg to 700 mg, more preferably 5 mg to 100 mg of a compoundof the Formula I, depending on the condition being treated, the route ofadministration and the age, weight and condition of the patient. Suchunit doses may therefore be administered more than once a day. Preferredunit dosage compositions are those containing a daily dose or sub-dose(for administration more than once a day), as herein above recited, oran appropriate fraction thereof, of an active ingredient. Furthermore,such pharmaceutical compositions may be prepared by any of the methodswell known in the pharmacy art.

Pharmaceutical compositions of the present invention may be adapted foradministration by any appropriate route, for example by the oral(including buccal or sublingual), rectal, topical, inhaled, nasal,ocular, sublingual, subcutaneous, local or parenteral (includingintravenous and intramuscular) route, and the like, all in unit dosageforms for administration.

Such compositions may be prepared by any method known in the art ofpharmacy, for example by bringing into association the active ingredientwith the carrier(s) or excipient(s). Dosage forms include tablets,troches, dispersions, suspensions, solutions, capsules, creams,ointments, aerosols, and the like.

In a further embodiment, the present invention provides a pharmaceuticalcomposition adapted for administration by the oral route, for treating,for example, rheumatoid arthritis.

In a further embodiment, the present invention provides a pharmaceuticalcomposition adapted for administration by the nasal route, for treating,for example, allergic rhinitis.

In a further embodiment, the present invention provides a pharmaceuticalcomposition adapted for administration by the inhaled route, fortreating, for example, asthma, Chronic Obstructive Pulmonary disease(COPD) or Acute Respiratory Distress Syndrome (ARDS).

In a further embodiment, the present invention provides a pharmaceuticalcomposition adapted for administration by the ocular route, fortreating, diseases of the eye, for example, conjunctivitis.

In a further embodiment, the present invention provides a pharmaceuticalcomposition adapted for administration by the parenteral (includingintravenous) route, for treating, for example, cancer.

For parenteral administration, the pharmaceutical composition of theinvention may be presented in unit-dose or multi-dose containers, e.g.injection liquids in predetermined amounts, for example in sealed vialsand ampoules, and may also be stored in a freeze dried (lyophilized)condition requiring only the addition of sterile liquid carrier, e.g.water, prior to use.

Mixed with such pharmaceutically acceptable auxiliaries, e.g. asdescribed in the standard reference, Gennaro, A. R. et al., Remington:The Science and Practice of Pharmacy (20th Edition., Lippincott Williams& Wilkins, 2000, see especially Part 5: Pharmaceutical Manufacturing),the active agent may be compressed into solid dosage units, such aspills, tablets, or be processed into capsules or suppositories. By meansof pharmaceutically acceptable liquids the active agent can be appliedas a fluid composition, e.g. as an injection preparation, in the form ofa solution, suspension, emulsion, or as a spray, e.g. a nasal spray.

For making solid dosage units, the use of conventional additives such asfillers, colorants, polymeric binders and the like is contemplated. Ingeneral any pharmaceutically acceptable additive which does notinterfere with the function of the active compounds can be used.Suitable carriers with which the active agent of the invention can beadministered as solid compositions include lactose, starch, cellulosederivatives and the like, or mixtures thereof, used in suitable amounts.For parenteral administration, aqueous suspensions, isotonic salinesolutions and sterile injectable solutions may be used, containingpharmaceutically acceptable dispersing agents and/or wetting agents,such as propylene glycol or butylene glycol.

Pharmaceutical compositions of the present invention which are adaptedfor oral administration may be presented as discrete units such ascapsules or tablets; powders or granules; solutions or suspensions inaqueous or non-aqueous liquids; edible foams or whips; or oil-in-waterliquid emulsions or water-in-oil liquid emulsions.

For instance, for oral administration in the form of a tablet orcapsule, the active drug component can be combined with an oral,non-toxic pharmaceutically acceptable inert carrier such as ethanol,glycerol, water and the like. Powders are prepared by comminuting thecompound to a suitable fine size and mixing with a similarly comminutedpharmaceutical carrier such as an edible carbohydrate, as, for example,starch or mannitol. Flavoring, preservative, dispersing and coloringagent can also be present.

Capsules are made by preparing a powder mixture, as described above, andfilling formed gelatin sheaths. Glidants and lubricants such ascolloidal silica, talc, magnesium stearate, calcium stearate or solidpolyethylene glycol can be added to the powder mixture before thefilling operation. A disintegrating or solubilizing agent such asagar-agar, calcium carbonate or sodium carbonate can also be added toimprove the availability of the medicament when the capsule is ingested.

Moreover, when desired or necessary, suitable binders, lubricants,disintegrating agents and coloring agents can also be incorporated intothe mixture. Suitable binders include starch, gelatin, natural sugarssuch as glucose or beta-lactose, corn sweeteners, natural and syntheticgums such as acacia, tragacanth or sodium alginate,carboxymethylcellulose, polyethylene glycol, waxes and the like.Lubricants used in these dosage forms include sodium oleate, sodiumstearate, magnesium stearate, sodium benzoate, sodium acetate, sodiumchloride and the like. Disintegrators include, without limitation,starch, methyl cellulose, agar, bentonite, xanthan gum and the like.Tablets are formulated, for example, by preparing a powder mixture,granulating or slugging, adding a lubricant and disintegrant andpressing into tablets. A powder mixture is prepared by mixing thecompound, suitably comminuted, with a diluent or base as describedabove, and optionally, with a binder such as carboxymethylcellulose, analiginate, gelatin, or polyvinyl pyrrolidone, a solution retardant suchas paraffin, a resorption accelerator such as a quaternary salt and/oran absorption agent such as bentonite, kaolin or dicalcium phosphate.The powder mixture can be granulated by wetting with a binder such assyrup, starch paste, acadia mucilage or solutions of cellulosic orpolymeric materials and forcing through a screen. As an alternative togranulating, the powder mixture can be run through the tablet machineand the result is imperfectly formed slugs broken into granules. Thegranules can be lubricated to prevent sticking to the tablet formingdies by means of the addition of stearic acid, a stearate salt, talc ormineral oil. The lubricated mixture is then compressed into tablets. Thecompounds of the present invention can also be combined with a freeflowing inert carrier and compressed into tablets directly without goingthrough the granulating or slugging steps. A clear or opaque protectivecoating consisting of a sealing coat of shellac, a coating of sugar orpolymeric material and a polish coating of wax can be provided.Dyestuffs can be added to these coatings to distinguish different unitdosages.

Oral fluids such as solution, syrups and elixirs can be prepared indosage unit form so that a given quantity contains a predeterminedamount of the compound. Syrups can be prepared by dissolving thecompound in a suitably flavored aqueous solution, while elixirs areprepared through the use of a non-toxic alcoholic vehicle. Suspensionscan be formulated by dispersing the compound in a non-toxic vehicle.Solubilizers and emulsifiers such as ethoxylated isostearyl alcohols andpolyoxy ethylene sorbitol ethers, preservatives, flavor additive such aspeppermint oil or natural sweeteners or saccharin or other artificialsweeteners, and the like can also be added.

Where appropriate, dosage unit compositions for oral administration canbe microencapsulated. The formulation can also be prepared to prolong orsustain the release, for example, by coating or embedding particulatematerial in polymers, wax or the like.

The compounds of Formula I, and salts, solvates and physiologicalfunctional derivatives thereof, can also be administered in the form ofliposome delivery systems, such as small unilamellar vesicles, largeunilamellar vesicles and multilamellar vesicles. Liposomes can be formedfrom a variety of phospholipids, such as cholesterol, stearylamine orphosphatidylcholines.

The compounds of Formula I and salts, solvates and physiologicalfunctional derivatives thereof may also be delivered by the use ofmonoclonal antibodies as individual carriers to which the compoundmolecules are coupled. The compounds may also be coupled with solublepolymers as targetable drug carriers. Such polymers can includepolyvinylpyrrolidone, pyran copolymer,polyhydroxypropylmethacrylamide-phenol,polyhydroxyethylaspartamidephenol, or polyethyleneoxidepolylysinesubstituted with palmitoyl residues. Furthermore, the compounds may becoupled to a class of biodegradable polymers useful in achievingcontrolled release of a drug, for example, polylactic acid, polyepsiloncaprolactone, polyhydroxy butyric acid, polyorthoesters, polyacetals,polydihydropyrans, polycyanoacrylates and cross-linked or amphipathicblock copolymers of hydrogels.

Dosage forms for inhaled administration may conveniently be formulatedas aerosols or dry powders.

For compositions suitable and/or adapted for inhaled administration, itis preferred that the compound or salt of Formula I is in aparticle-size-reduced form, and more preferably the size-reduced form isobtained or obtainable by micronisation. The preferable particle size ofthe size-reduced (e.g. micronised) compound or salt or solvate isdefined by a D50 value of about 0.5 to about 10 microns (for example asmeasured using laser diffraction).

Aerosol formulations, e.g. for inhaled administration, can comprise asolution or fine suspension of the active substance in apharmaceutically acceptable aqueous or non-aqueous solvent. Aerosolformulations can be presented in single or multidose quantities insterile form in a sealed container, which can take the form of acartridge or refill for use with an atomising device or inhaler.Alternatively the sealed container may be a unitary dispensing devicesuch as a single dose nasal inhaler or an aerosol dispenser fitted witha metering valve (metered dose inhaler) which is intended for disposalonce the contents of the container have been exhausted.

Where the dosage form comprises an aerosol dispenser, it preferablycontains a suitable propellant under pressure such as compressed air,carbon dioxide or an organic propellant such as a hydrofluorocarbon(HFC). Suitable HFC propellants include 1,1,1,2,3,3,3-heptafluoropropaneand 1,1,1,2-tetrafluoroethane. The aerosol dosage forms can also takethe form of a pump-atomiser. The pressurised aerosol may contain asolution or a suspension of the active compound. This may require theincorporation of additional excipients e.g. co-solvents and/orsurfactants to improve the dispersion characteristics and homogeneity ofsuspension formulations. Solution formulations may also require theaddition of co-solvents such as ethanol. Other excipient modifiers mayalso be incorporated to improve, for example, the stability and/or tasteand/or fine particle mass characteristics (amount and/or profile) of theformulation.

For pharmaceutical compositions suitable and/or adapted for inhaledadministration, it is preferred that the pharmaceutical composition is adry powder inhalable composition. Such a composition can comprise apowder base such as lactose, glucose, trehalose, mannitol or starch, thecompound of Formula I or salt or solvate thereof (preferably inparticle-size-reduced form, e.g. in micronised form), and optionally aperformance modifier such as L-leucine or another amino acid, and/ormetals salts of stearic acid such as magnesium or calcium stearate.Preferably, the dry powder inhalable composition comprises a dry powderblend of lactose and the compound of Formula I or salt thereof. Thelactose is preferably lactose hydrate e.g. lactose monohydrate and/or ispreferably inhalation-grade and/or fine-grade lactose. Preferably, theparticle size of the lactose is defined by 90% or more (by weight or byvolume) of the lactose particles being less than 1000 microns(micrometers) (e.g. 10-1000 microns e.g. 30-1000 microns) in diameter,and/or 50% or more of the lactose particles being less than 500 microns(e.g. 10-500 microns) in diameter. More preferably, the particle size ofthe lactose is defined by 90% or more of the lactose particles beingless than 300 microns (e.g. 10-300 microns e.g. 50-300 microns) indiameter, and/or 50% or more of the lactose particles being less than100 microns in diameter. Optionally, the particle size of the lactose isdefined by 90% or more of the lactose particles being less than 100-200microns in diameter, and/or 50% or more of the lactose particles beingless than 40-70 microns in diameter. It is preferable that about 3 toabout 30% (e.g. about 10%) (by weight or by volume) of the particles areless than 50 microns or less than 20 microns in diameter. For example,without limitation, a suitable inhalation-grade lactose is E9334 lactose(10% fines) (Borculo Domo Ingredients, Hanzeplein 25, 8017 J D Zwolle,Netherlands).

Optionally, in particular for dry powder inhalable compositions, apharmaceutical composition for inhaled administration can beincorporated into a plurality of sealed dose containers (e.g. containingthe dry powder composition) mounted longitudinally in a strip or ribboninside a suitable inhalation device. The container is rupturable orpeel-openable on demand and the dose of e.g. the dry powder compositioncan be administered by inhalation via the device such as the DISKUS®device(GlaxoSmithKline). Other dry powder inhalers are well known tothose of ordinary skill in the art, and many such devices arecommercially available, with representative devices including Aerolizer®(Novartis), Airmax™ (IVAX), ClickHaler® (Innovata Biomed), Diskhaler®(GlaxoSmithKline), Accuhaler (GlaxoSmithKline), Easyhaler® (OrionPharma), Eclipse™ (Aventis), FlowCaps® (Hovione), Handihaler®(Boehringer Ingelheim), Pulvinal® (Chiesi), Rotahaler®(GlaxoSmithKline), SkyeHaler™ or Certihaler™ (SkyePharma), Twisthaler(Schering-Plough), Turbuhaler® (AstraZeneca), Ultrahaler® (Aventis), andthe like.

Dosage forms for ocular administration may be formulated as solutions orsuspensions with excipients suitable for ophthalmic use.

Dosage forms for nasal administration may conveniently be formulated asaerosols, solutions, drops, gels or dry powders.

Pharmaceutical compositions adapted for administration by inhalationinclude fine particle dusts or mists, which may be generated by means ofvarious types of metered, dose pressurized aerosols, nebulizers orinsufflators.

For pharmaceutical compositions suitable and/or adapted for intranasaladministration, the compound of Formula I or a pharmaceuticallyacceptable salt or solvate thereof may be formulated as a fluidformulation for delivery from a fluid dispenser. Such fluid dispensersmay have, for example, a dispensing nozzle or dispensing orifice throughwhich a metered dose of the fluid formulation is dispensed upon theapplication of a user-applied force to a pump mechanism of the fluiddispenser. Such fluid dispensers are generally provided with a reservoirof multiple metered doses of the fluid formulation, the doses beingdispensable upon sequential pump actuations. The dispensing nozzle ororifice may be configured for insertion into the nostrils of the userfor spray dispensing of the fluid formulation into the nasal cavity. Afluid dispenser of the aforementioned type is described and illustratedin WO-A-2005/044354, the entire content of which is hereby incorporatedherein by reference. The dispenser has a housing which houses a fluiddischarge device having a compression pump mounted on a container forcontaining a fluid formulation. The housing has at least onefinger-operable side lever which is movable inwardly with respect to thehousing to cam the container upwardly in the housing to cause the pumpto compress and pump a metered dose of the formulation out of a pumpstem through a nasal nozzle of the housing. A particularly preferredfluid dispenser is of the general type illustrated in FIGS. 30-40 ofWO-A-2005/044354.

The invention further includes a pharmaceutical composition of acompound of Formula I or pharmaceutically acceptable salts thereof, ashereinbefore described, in combination with packaging material suitablefor said composition, said packaging material including instructions forthe use of the composition for the use as hereinbefore described.

The following are examples of representative pharmaceutical dosage formsfor the compounds of this invention:

Injectable Suspension (I.M.) mg/ml

Compound of Formula I 10 Methylcellulose 5.0 Tween 80 0.5 Benzyl alcohol9.0 Benzalkonium chloride 1.0 Water for injection to a total volume of 1mlTablet mg/Tablet

Compound of Formula I 25 Microcrystalline Cellulose 415 Providone 14.0Pregelatinized Starch 43.5 Magnesium Stearate 2.5 500Capsule mg/Capsule

Compound of Formula I 25 Lactose Powder 573.5 Magnesium Stearate 1.5 600Aerosol Per Canister

Compound of Formula I   24 mg Lecithin, NF Liquid Concentrate  1.2 mgTrichlorofluoromethane, NF 4.025 gm Dichlorodifluoromethane, NF 12.15 gm

It will be appreciated that when the compound of the present inventionis administered in combination with other therapeutic agents normallyadministered by the inhaled, intravenous, oral or intranasal route, thatthe resultant pharmaceutical composition may be administered by the sameroutes.

It should be understood that in addition to the ingredients particularlymentioned above, the compositions may include other agents conventionalin the art having regard to the type of formulation in question, forexample those suitable for oral administration may include flavoringagents.

A therapeutically effective amount of a compound of the presentinvention will depend upon a number of factors including, for example,the age and weight of the animal, the precise condition requiringtreatment and its severity, the particular compound having Formula I,the nature of the formulation, and the route of administration, and willultimately be at the discretion of the attendant physician orveterinarian. However, an effective amount of a compound of Formula Ifor the treatment of diseases or conditions associated withinappropriate Btk activity, will generally be in the range of 5 μg to100 mg/kg body weight of recipient (mammal) per day and more usually inthe range of 5 μg to 10 mg/kg body weight per day. This amount may begiven in a single dose per day or more usually in a number (such as two,three, four, five or six) of sub-doses per day such that the total dailydose is the same. An effective amount of a salt or solvate, thereof, maybe determined as a proportion of the effective amount of the compound ofFormula I per se.

In general parenteral administration requires lower dosages than othermethods of administration which are more dependent upon absorption.However, a dosage for humans preferably contains 0.0001-25 mg of acompound of Formula I or pharmaceutically acceptable salts thereof perkg body weight. The desired dose may be presented as one dose or asmultiple subdoses administered at appropriate intervals throughout theday, or, in case of female recipients, as doses to be administered atappropriate daily intervals throughout the menstrual cycle. The dosageas well as the regimen of administration may differ between a female anda male recipient.

General Synthesis

The compounds of the present invention can be prepared by methods wellknown in the art of organic chemistry. See, for example, J. March,‘Advanced Organic Chemistry’ 4^(th) Edition, John Wiley and Sons. Duringsynthetic sequences it may be necessary and/or desirable to protectsensitive or reactive groups on any of the molecules concerned. This isachieved by means of conventional protecting groups, such as thosedescribed in T. W. Greene and P. G. M. Wutts ‘Protective Groups inOrganic Synthesis’ 3^(rd) Edition, John Wiley and Sons, 1999. Theprotective groups are optionally removed at a convenient subsequentstage using methods well known in the art.

The products of the reactions are optionally isolated and purified, ifdesired, using conventional techniques, but not limited to, filtration,distillation, crystallization, chromatography and the like. Suchmaterials are optionally characterized using conventional means,including physical constants and spectral data.

The compounds of Formula I can be prepared by the general syntheticroute shown in the scheme below.

Reduction of 3-chloropyrazine-2-carbonitrile (II) can be accomplished byhydrogenation in the presence of a suitable catalyst system and solvent,for example Raney-Nickel ethanol to provide(3-chloropyrazin-2-yl)methanamine (III). This amine can then be reactedwith the diacid monoester (IV). The reaction of IV can be carried out ina solvent such as DMF, THF or DCM in the presence of a base such asDIPEA, N-methylmorpholine, 4-DMAP or triethylamine and in the presenceof a coupling reagent such as PyBOP, TBTU, EDCI or HATU to formN-((3-chloropyrazin-2-yl)methyl)amide (V). Cyclization chloropyrazine(V) can be performed using condensation reagents likephosphorusoxychloride under heating conditions to provide the8-chloroimidazo[1,5-a]pyrazine derivatives VI. Subsequent brominationcan be accomplished using bromine or N-bromosuccinimide in a suitablesolvent like DCM or DMF at appropriate temperature to obtain compoundsof formula VII. 8-Aminoimidazo[1,5-a]pyrazine derivatives (VIII) can beprepared from compounds VII using ammonia(gas) in isopropanol atelevated temperature in a pressure vessel (>4 atm) or with primary amine(such as dimethoxybenzylamine) under heating. Compounds of formula I canbe prepared from compounds of formula VIII using an appropriate boronicacid or pinacol ester (IX), in the presence of a suitable palladiumcatalyst system, for example bis(diphenylphosphino)ferrocenepalladium(II)chloride complex ortetrakis(triphenylphosphine)palladium(0) in the presence of an inorganicbase like potassium carbonate, cesium carbonate or potassium phosphatein a suitable solvent system like combinations of dioxane and water.Palladium catalysts and conditions to form either the pinacol esters orto couple the boronic acids or pinacol esters with the1-bromoimidazo[1,5-a]pyrazin-8-amine are well known to the skilledorganic chemist—see, for example, Ei-ichi Negishi (Editor), Armin deMeijere (Associate Editor), Handbook of Organopalladium Chemistry forOrganic Synthesis, John Wiley and Sons, 2002. The ester usually ishydrolyzed during the Suzuki coupling with water as co-solvent,otherwise one additional step for the hydrolysis of ester underconventional basic or acid conditions. The diacid mono esters IV arecommercially available or can be readily prepared using methods wellknown to the skilled organic chemist.

Several routes for the preparation of the biaryl tertiary alcoholboronic ester IX are shown in Scheme II. Route 1 use Weinreb amide X toreact with the aromatic metallic reagent XI to provide ketone XII, whichthen reacts with alkyl lithium or Grinard reagent to provideintermediate XII. The bromo in XII can be converted to boronic esterusing palladium catalized conversion. The difference of Route 2 andRoute 1 is that Route 2 utilizes the Weinreb amide XIV and metallicreagent XV for the first step. Route 3 apply the commercially availableor readily prepared methal ketone XVIII to react with the aromaticmetallic reagent XI to form the tertiary alcohol XV, in which the bromowas later converted to the boronic ester.

The invention is illustrated by the following examples.

EXAMPLES

The following examples are illustrative embodiments of the invention,not limiting the scope of the invention in any way. Reagents arecommercially available or are prepared according to procedures in theliterature.

Mass Spectrometry: Electron Spray spectra were recorded on the AppliedBiosystems API-165 single quad mass spectrometer in alternating positiveand negative ion mode using Flow Injection. The mass range was 120-2000Da. and scanned with a step rate of 0.2 Da. and the capillary voltagewas set to 5000 V. N₂ gas was used for nebulisation.

LC-MS spectrometer (Waters) Detector: PDA (200-320 nm), Mass detector:ZQ and Eluent: A: acetonitrile with 0.05% trifluoroacetic acid, B:acetronitrile/water=1/9 (v/v) with 0.05% trifluoroacetic acid.

Method A: LC-MS

Column Ascentis Express C18, 100 × 3.0 mm, 2.7 μm A: H₂O (0.1% TFA)Mobile Phase B: MeCN (0.05% TFA) Stop Time: 5.0 min Time (min) B % 0.0010 3.50 99 4.99 99 Gradient 5.00 10 Sample injection 2 μl volume FlowRate 1.00 ml/min Wavelength 220 nm Oven Tem. 50° C. MS polarity ESI POSMethod B: LC-MS

Column Ascentis Express C18, 50 × 2.1 mm, 5 μm A: H₂O (0.1% TFA) MobilePhase B: MeCN (0.05% TFA) Stop Time: 2.0 min Time (min) B % 0 10 0.8 991.99 99 Gradient 2.00 10 Sample injection 2 μl volume Flow Rate 1.25ml/min Wavelength 220 nm Oven Temp. 50° C. MS polarity ESI POSMethod C:Sample Info: Easy-Access Method: ‘1-Short_TFA_Pos’Method Info: B222 Column Agilent SBC (3.0×50 mm, 1.8 m); Flow 1.0mL/min; solvent A: H₂O-0.1% TFA;solvent B: MeCN-0.1% TFA;GRADIENT TABLE: 0 min: 10% B, 0.3 min: 10% B, 1.5 min: 95% B, 2.70 min:95% B, 2.76 min: 10% Bstop time 3.60 min, PostTime 0.70 min.Method D:Sample Info: Easy-Access Method: ‘1_Fast’Method Info: A330 Column Agilent Zorbax SB-C18 (2.1×30 mm, 3.5 m); Flow2.0 mL/min;solvent A: H₂O-0.1% TFA;solvent B: MeCN-0.1% TFA;GRADIENT TABLE: 0.01 min: 10% B, 1.01 min: 95% B, 1.37 min: 95% B, 1.38min: 10% B,stop time 1.7 min, PostTime=OFF

The following abbreviations are used throughout the application withrespect to chemical terminology:

-   HATU O-(7-Azabenzotriazol-1-yl)-1,1,3,3-tetramethyluroniumhexafluoro    phosphate-   Cbz Benzyloxycarbonyl-   D Deuterated hydrogen-   DMF N,N-Dimethylformamide-   DCM Dichloromethane-   EA Ethyl acetate-   EtOAc Ethyl acetate-   DIPEA N,N-Diisopropylethylamine-   THF Tetrahydrofuran-   EtOH Ethanol-   EDCI.HCl 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride-   4-DMAP 4-Dimethylaminopyridine-   PyBOP    O-Benzotriazole-1-yl-oxy-trispyrrolidinophosphoniumhexafluorophosphat-   TBTU O-Benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium    tetrafluoroborate-   HBr Hydrogen bromide-   HCl Hydrogen chloride-   HOAc Acetic acid-   POCl₃ Phosphorous oxychloride-   HPLC High Pressure Liquid Chromatography-   UPLC Ultra Performance Liquid Chromatography-   LiHMDS Lithium hexamethyldisilazide-   MeOH Methanol-   DCM Dichloromethane-   n-BuLi n-Butyllithium-   CO₂ Carbondioxide-   NaHCO₃ Sodium bicarbonate-   K₃PO₄ Potassium phosphate-   P(Cy)₃ Tricyclohexylphosphine-   Pd(OAc)₂ Palladium(II) acetate-   Na₂SO₄ Sodium sulfate-   Na₂CO₃ Sodium carbonate-   DAST Diethylaminosulfur trifluoride-   Cs₂CO₃ Cesium carbonate-   Et₂O Diethylether-   Na₂S₂O₃ Sodium thiosulfate-   Na₂S₂O₄ Sodium hydrosulfite-   NaCNBH₃ Sodium cyanoborohydride-   NH₄Cl Ammonium chloride-   MgSO₄ Magnesium sulfate-   LiOH Lithium hydroxide-   IPA Isopropylamine-   TFA Trifluoroacetic acid-   Cbz-Cl Benzylchloroformate-   PE Petroleum ether-   EA Ethyl acetate-   NaHMDS Sodium hexamethyldisilazide-   10% Pd/C 10% Palladium on carbon-   TEA Triethylamine-   CDI 1,1′-Carbonyl diimidazole-   DMI 1,3-Dimethyl-2-imidazolidinone-   NBS N-Bromosuccinimide-   i-PrOH 2-Propanol-   K₂CO₃ Potassium carbonate-   Pd(dppf)Cl₂ 1,1′-Bis(diphenylphosphino)ferrocene palladium (II)    chloride, complex with dichloromethane-   Et₃N Triethylamine-   2-BuOH 2-Butanol-   LCMS Liquid Chromatography/Mass Spectrometry-   MeCN Acetonitrile-   NH₃ Ammonia-   CD₃I Trideuteromethyl iodide-   CD₃OD Tetradeuteromethanol-   CH₃I Iodomethane-   CBr₄ Carbon tetrabromide-   Tris-HCl Tris(hydroxymethyl)aminomethane hydrochloride-   MgCl₂ Magnesium chloride-   NaN₃ Sodium azide-   DTT Dithiothreitol-   DMSO Dimethyl sulfoxide-   IMAP Immobilized Metal Ion Affinity-Based Fluorescence Polarization-   ATP Adenosine triphosphate-   MnCl₂ Manganese(II) chloride-   DMA Dimethylacetamide-   IPA Isopropyl alcohol-   TPP triphenylphosphine-   DIAD Diisopropyl azodicarboxylate-   DMB 2,4-dimethoxybenzyl-   DCE Dichloroethane-   DEAD Diethyl azodicarboxylate-   ACN Acetonitrile-   Ret. Time Retention Time-   RT (rt) Room Temperature-   Aq Aqueous-   EtOH Ethanol-   MPLC Medium Pressure Liquid Chromatography    Xantphos 4,5-Bis(diphenylphosphino)-9,9-dimethylxanthene    X-phos 2-Dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl

INTERMEDIATES Intermediate 1aE1, 1aE2, 1bE1 and 1bE2

(1S, 3R)3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid (1R, 3S)3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid (1R, 3R)3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid (1S, 3S)3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid Step 1: dimethyl cyclopentane-1,3-dicarboxylate

To a solution of 3-(methoxycarbonyl)cyclopentanecarboxylic acid (18 g,104.6 mmol) in MeOH (200 mL) was added H₂SO₄ (30.8 g, 313.9 mmol). Themixture was stirred at 70° C. for 2 h. The solvent was concentrated andthe residue was purified by column chromatography on silica gel elutedwith PE/EA=4/1 to give dimethyl cyclopentane-1,3-dicarboxylate. ¹H NMR(CDCl₃, 400 MHz) δ 1.85-2.01 (m, 4H), 2.04-2.12 (m, 1H), 2.18-2.26 (m,1H), 2.69-2.87 (m, 2H), 3.66 (s, 6H) ppm.

Step 2: dimethyl 1-isopropylcyclopentane-1,3-dicarboxylate

To a solution of LDA (14.8 mL, 29.6 mmol) in THF (80 mL) and HMPT (19.2g, 107.5 mmol) at −65° C. was added dropwise a solution of dimethylcyclopentane-1,3-dicarboxylate (5 g, 26.9 mmol) in THF (20 mL). Themixture was stirred at −65° C. for 10 min, 2-iodopropane (9.1 g, 53.8mmol) was then added dropwise and the resulting mixture was stirred atroom temperature for 4 h. The reaction mixture was quenched withsaturated NH₄Cl solution and extracted with EA. The organic layer wasdried and concentrated, the residue was purified by columnchromatography on silica gel eluted with PE/EA=10/1 to give dimethyl1-isopropylcyclo pentane-1,3-dicarboxylate. ¹H NMR (CDCl₃, 400 MHz) δ0.78-0.95 (m, 6H), 1.47-1.79 (m, 2H), 1.82-2.00 (m, 3H), 2.11-2.30 (m,1H), 2.35-2.52 (m, 1H), 2.69-2.85 (m, 1H), 3.59-3.70 (m, 6H) ppm.

Step 3: 3-isopropyl-3-(methoxycarbonyl)cyclopentanecarboxylic acid

To a solution of dimethyl 1-isopropylcyclopentane-1,3-dicarboxylate (5.4g, 23.7 mmol) in THF/MeOH/H₂O (50 mL/50 mL/20 mL) was added LiOH.H₂O (3g, 71.1 mmol). The mixture was stirred at room temperature for 4 h. Thereaction mixture was diluted with water, acidified by 1 M HCl, andextracted with EA. The organic layer was dried and concentrated. Theresidue was used in next step directly.

Step 4: methyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-1-isopropylcyclopentanecarboxylate

To a solution of 3-isopropyl-3-(methoxycarbonyl)cyclopentanecarboxylicacid (5.1 g, 23.8 mmol) in THF (130 mL) was added(3-chloropyrazin-2-yl)methanamine (6.4 g, 35.7 mmol), HATU (13.6 g, 35.7mmol) and TEA (14.4 g, 143 mmol). The mixture was stirred at roomtemperature overnight. The reaction mixture was treated with EA andwater, the organic layer was dried and concentrated. The residue waspurified by column chromatography on silica gel eluted with PE/THF=10/1to give methyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-1-isopropylcyclopentanecarboxylate.¹H NMR (CDCl₃, 400 MHz) δ 0.89-0.94 (m, 6H), 1.62-1.82 (m, 2H),1.91-2.29 (m, 4H), 2.43-2.55 (m, 1H), 2.77-2.93 (m, 1H), 3.70 (d, J=3.52Hz, 3H), 4.65-4.78 (m, 2H), 8.33-8.39 (m, 1H), 8.45-8.52 (m, 1H) ppm.

Step 5: methyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylate

To a solution of methyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-1-isopropylcyclopentanecarboxylate (2 g, 5.9 mmol) in MeCN (100 mL) was added PCl₅ (2.45 g,11.8 mmol). The mixture was stirred at 65° C. for 2 h. The reactionsolution was treated with DCM and aq. NaHCO₃. The organic layer wasdried and concentrated. The residue was purified by columnchromatography on silica gel eluted with DCM/THF=50/1 to give methyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylate.MS-ESI (m/z): 322 [M+1]⁺

Step 6: methyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylate

To a solution of methyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylate(1.7 g, 5.3 mmol) in DMF (30 mL) was added a solution of NBS (1 g, 5.8mmol) in DMF (10 mL). The mixture was stirred at room temperature for 1h. The reaction mixture was treated with EA and water, the organic layerwas dried and concentrated. The residue was purified by columnchromatography on silica gel eluted with DCM/THF=50/1 to give methyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylate.MS-ESI (m/z): 402 [M+1]⁺

Step 7: methyl3-(1-bromo-8-((2,4-dimethoxybenzyl)amino)imidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylate

To a solution of methyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylate (2 g, 5 mmol) in DMF (40 mL) was added K₂CO₃ (1.38 g,10 mmol) and (2,4-dimethoxyphenyl)methanamine (921 mg, 5.5 mmol). Themixture was stirred at 90° C. for 6 h. The reaction mixture was treatedwith EA and water. The organic layer was dried and concentrated. Theresidue was purified by column chromatography on silica gel eluted withPE/DCM/EA=1/1/0.2 to give methyl 3-(1-bromo-8-((2,4-dimethoxybenzyl)amino)imidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylate.¹H NMR (CDCl₃, 400 MHz) δ 0.74-0.93 (m, 6H), 1.10-1.28 (m, 1H),1.52-1.64 (m, 1H), 1.73-1.83 (m, 1H), 1.97-2.10 (m, 3H), 2.33-2.47 (m,1H), 3.15-3.28 (m, 1H), 3.55-3.69 (m, 3H), 3.73 (s, 3H), 3.81 (s, 3H),4.59 (d, J=5.6 Hz, 2H), 6.34-6.47 (m, 2H), 6.59-6.68 (m, 1H), 6.94-7.03(m, 2H), 7.16-7.23 (m, 1H) ppm.

Step 8:3-(1-bromo-8-((2,4-dimethoxybenzyl)amino)imidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylic acid

To a solution of methyl3-(1-bromo-8-((2,4-dimethoxybenzyl)amino)imidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylate(1.2 g, 2.26 mmol) in MeOH (40 mL) was added KOH (1.6 g, 29.4 mmol) and18-Crown-6 (200 mg). The mixture was stirred at 80° C. overnight. Thenthe mixture was added THF/H₂O (20 mL/10 mL), and stirred at 80° C. forfurther 3 days. The reaction was neutralized with 2 M HCl and extractedwith EA. The organic layer was dried and concentrated. The residue waspurified by column chromatography on silica gel eluted with DCM/EA=2/1to give3-(1-bromo-8-((2,4-dimethoxybenzyl)amino)imidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid. MS-ESI (m/z): 517 [M+1]+.

Step 9:3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid

A solution of3-(1-bromo-8-((2,4-dimethoxybenzyl)amino)imidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid (1 g, 1.9 mmol) in TFA (6 mL) was heated to reflux for 2 h. Themixture was concentrated and the residue was purified by pre-HPLC togivecis-3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid (350 mg), andtrans-3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid (300 mg), which were separated with SFC to give(1S,3R)-3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid (100 mg),(1R,3S)-3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid (90 mg),(1R,3R)-3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid (90 mg) and(1S,3S)-3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid (120 mg). SFC condition: For cis mixture: “Column: Chiralpak AD-H250×4.6 mm I.D., 5 um Mobile phase: ethanol (0.05% DEA) in CO₂ from 5%to 40% Flow rate: 2.35 mL/min Wavelength: 220 nm”.

¹H NMR (CD₃OD, 400 MHz) δ 0.97 (dd, J=11.17, 6.90 Hz, 6H), 1.69-1.82 (m,1H), 2.01-2.23 (m, 4H), 2.40-2.59 (m, 2H), 3.48-3.61 (m, 1H), 6.92 (d,J=6.0 Hz, 1H), 7.71 (d, J=6.0 Hz, 1H) ppm.

For trans mixture: “Column: Chiralpak AD-H 250×4.6 mm I.D., 5 um Mobilephase: ethanol (0.05% DEA) in CO₂ from 5% to 40% Flow rate: 2.35 mL/minWavelength: 220 nm”.

¹H NMR (CD₃OD, 400 MHz) δ 0.98 (dd, J=10.92, 6.90 Hz, 6H), 1.88-1.98 (m,3H), 2.04-2.34 (m, 3H), 2.60-2.69 (m, 1H), 3.52-3.62 (m, 1H), 6.91 (d,J=6.0 Hz, 1H), 7.68 (d, J=6.0 Hz, 1H) ppm.

Intermediate 2

4-(8-Amino-1-bromo-imidazo[1,5-a]pyrazin-3-yl)-2,5-dioxo-bicyclo[2.2.2]octane-1-carboxylicacid Step 1: ethyl4′-(((3-chloropyrazin-2-yl)methyl)carbamoyl)dispiro[[1,3]dioxolane-2,2′-bicyclo[2.2.2]octane-5′,2″-[1,3]dioxolane]-1′-carboxylate

A solution of Dispiro [1, 3-dioxolane-2, 2′-bicyclo [2.2.2] octane-5′,2″-[1, 3] dioxolane]-1′, 4′-dicarboxylic acid (1 g, 2.92 mmol) in DCM(50 mL) was added (CClO)₂ (473 mg, 4.38 mmol) at 0° C., the mixture wasstirred at 25° C. for 1 hour. The mixture was concentrated to affordDispiro [1, 3-dioxolane-2, 2′-bicyclo [2.2.2] octane-5′, 2″-[1, 3]dioxolane]-1′, 4′-dicarboxylic acyl chloride. To a solution of Dispiro[1, 3-dioxolane-2, 2′-bicyclo [2.2.2] octane-5′, 2″-[1, 3]dioxolane]-1′,4′-dicarboxylic acyl chloride in DCM (20 mL) was added(3-chloropyrazin-2-yl) methanamine (419.39 mg, 2.92 mmol) at 0° C., themixture was stirred at 25° C. for 1 hour. H₂O (20 mL) was added to themixture, the mixture was extracted by EA (50 mL). The organic layer waswashed with H₂O (30 mL) and brine (30 mL), dried over Na₂SO₄,concentrated to afford the crude product, which was purified on silicagel chromatography with the eluent of PE:THF (5:1-1:1) to give the titlecompound as solid.

¹H NMR (400 MHz, CDCl₃) δ=8.42 (d, J=1.6 Hz, 1H), 8.29 (br. s., 1H),7.89 (br. s., 1H), 7.24 (s, 1H), 5.27 (s, 1H), 4.77-4.55 (m, 2H),4.16-3.88 (m, 7H), 3.86-3.67 (m, 3H), 2.47-2.32 (m, 2H), 2.27 (s, 2H),2.16-2.05 (m, 1H), 2.01-1.79 (m, 3H), 1.75-1.59 (m, 3H), 1.23 (t, J=7.0Hz, 3H) ppm.

Step 2: ethyl4′-(8-chloroimidazo[1,5-a]pyrazin-3-yl)dispiro[[1,3]dioxolane-2,2′-bicyclo[2.2.2]octane-5′,2″-[1,3]dioxolane]-1′-carboxylate

A solution of ethyl4′-(((3-chloropyrazin-2-yl)methyl)carbamoyl)dispiro[[1,3]dioxolane-2,2′-bicyclo[2.2.2]octane-5′,2″-[1,3]dioxolane]-1′-carboxylate(500 mg, 1.07 mmol) in ACN (20 mL) was added PCl₅ (1.11 g, 5.34 mmol) at0° C. under nitrogen, the mixture was stirred at 25° C. for 1 hour. Thesolution was added to aq NaHCO₃ at 0° C., and the mixture was extractedby DCM (20 mL). The organic layer was washed with H₂O (30 mL) and brine(30 mL), dried over anhydrous Na₂SO₄, concentrated to afford the crudeproduct which was purified on silica gel chromatography with the eluentof PE:THF (5:1-1:1) to give the product.

¹H NMR (400 MHz, CDCl₃) δ=8.32-8.29 (m, 1H), 8.38-8.27 (m, 1H),7.83-7.69 (m, 1H), 7.23-7.14 (m, 1H), 4.10 (q, J=7.0 Hz, 1H), 4.01-3.88(m, 3H), 3.81-3.63 (m, 3H), 3.42-3.34 (m, 1H), 2.97-2.88 (m, 1H), 2.78(d, J=6.3 Hz, 1H), 2.55 (d, J=16.8 Hz, 1H), 2.48-2.39 (m, 1H), 2.19 (d,J=14.1 Hz, 1H), 2.07 (d, J=14.5 Hz, 1H), 1.88-1.76 (m, 2H), 1.57 (br.s., 1H), 1.36 (s, 1H), 1.30-1.17 (m, 3H) ppm.

Step 3: ethyl1′-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)dispiro[[1,3]dioxolane-2,2′-bicyclo[2.2.2]octane-5′,2″-[1,3]dioxolane]-4′-carboxylate

A solution of ethyl4′-(8-chloroimidazo[1,5-a]pyrazin-3-yl)dispiro[[1,3]dioxolane-2,2′-bicyclo[2.2.2]octane-5′,2″-[1,3]dioxolane]-1′-carboxylate(230 mg, 0.52 mmol) in ACN (5 mL) was added NBS (120 mg, 0.68 mmol) at20° C. under nitrogen. The mixture was stirred at 25° C. for 1 hour. H₂O(10 mL) was added to the mixture, the mixture was extracted by EA (10mL). The organic layer was washed with H₂O (20 mL) and brine (20 mL),dried over anhydrous Na₂SO₄, concentrated to afford the crude product ofthe title compound.

¹H NMR (400 MHz, CDCl₃) δ=8.41 (d, J=5.1 Hz, 1H), 7.18 (d, J=5.1 Hz,1H), 4.14 (q, J=7.0 Hz, 2H), 4.04-3.93 (m, 4H), 3.89-3.72 (m, 4H),3.00-2.87 (m, 3H), 2.79-2.70 (m, 4H), 2.61-2.41 (m, 4H), 2.21 (d, J=14.1Hz, 2H), 2.15-1.99 (m, 2H), 1.90-1.76 (m, 2H), 1.26 (t, J=7.2 Hz, 4H)ppm.

Step 5: ethyl1′-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)dispiro[[1,3]dioxolane-2,2′-bicyclo[2.2.2]octane-5′,2″-[1,3]dioxolane]-4′-carboxylate

A solution of ethyl1′-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)dispiro[[1,3]dioxolane-2,2′-bicyclo[2.2.2]octane-5′,2″-[1,3]dioxolane]-4′-carboxylate(280 mg, 0.53 mmol) in i-PrOH (4 mL) was added NH₃H₂O (4 mL) at 25° C.The mixture was stirred at 100° C. for 16 hours in sealed tube. Afterthe reaction, the mixture was concentrated to afford the crude productwhich was purified on silica gel chromatography with the eluent ofPE:THF (5:1-1:1) to give the title compound.

¹H NMR (400 MHz, CDCl₃) δ=7.91 (d, J=5.1 Hz, 1H), 6.82 (d, J=5.5 Hz,1H), 4.09 (q, J=6.8 Hz, 2H), 3.98-3.86 (m, 3H), 3.81-3.63 (m, 5H), 3.47(d, J=6.3 Hz, 1H), 2.89-2.86 (m, 1H), 2.96-2.80 (m, 2H), 2.76-2.63 (m,2H), 2.57-2.34 (m, 3H), 2.22-2.00 (m, 3H), 1.24-1.17 (m, 4H) ppm.

Step 6:4-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2,5-dioxobicyclo[2.2.2]octane-1-carboxylic acid

A solution of ethyl1′-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)dispiro[[1,3]dioxolane-2,2′-bicyclo[2.2.2]octane-5′,2″-[1,3]dioxolane]-4′-carboxylate(140 mg, 0.27 mmol) in HCl (5 mL, 2M) was stirred at 90° C. for 1 hour.After the reaction, the mixture was concentrated to afford the crude thetitle compound as solid. MS: 393.0 (M+1)

Intermediate 3

ethyl1-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)cyclopropanecarboxylateStep 1: ethyl1-(((3-chloropyrazin-2-yl)methyl)carbamoyl)cyclopropanecarboxylate

To a solution of 1-(ethoxycarbonyl)cyclopropanecarboxylic acid (200 mg,1.265 mmol), (3-chloropyrazin-2-yl)methanamine (182 mg, 1.265 mmol),4-methylmorpholine (640 mg, 6.32 mmol) and HOBT (48.4 mg, 0.316 mmol) inMeCN (20 mL) was added EDC (242 mg, 1.265 mmol) and the reaction wasstirred at 20° C. for 16 hours. The solution was diluted with EtOAc (30mL), washed with water (20 mL×3), 1N HCl aqueous (30 mL), and brine (30mL). The organic layer was dried over Na₂SO₄, and concentrated in vacuoto give the title compound. ¹H NMR (400 MHz, CDCl₃) δ: 9.78 (br. s.,1H), 8.51 (br. s., 1H), 8.29 (br. s., 1H), 4.76 (d, J=4.3 Hz, 2H), 4.17(q, J=7.0 Hz, 2H), 1.77-1.65 (m, 2H), 1.58 (d, J=3.9 Hz, 2H), 1.25 (t,J=7.0 Hz, 3H) ppm.

Step 2: ethyl1-(8-chloroimidazo[1,5-a]pyrazin-3-yl)cyclopropanecarboxylate

A solution of compound ethyl1-(((3-chloropyrazin-2-yl)methyl)carbamoyl)cyclopropanecarboxylate (65mg, 0.229 mmol) and PCl₅ (143 mg, 0.687 mmol) in MeCN (15 mL) wasstirred at 80° C. for 2 hours and poured into 10% NaHCO₃ (50 mL). Themixture was extracted with EtOAc (20 mL×3). The combined organic layerswere dried over K₂CO₃ and concentrated in vacuo to give the titlecompound. MS: 252 (M+1). ¹H NMR (400 MHz, CDCl₃) δ: 7.80 (s, 1H), 7.68(d, J=5.1 Hz, 1H), 7.40 (d, J=5.1 Hz, 1H), 4.14 (q, J=7.2 Hz, 2H),1.93-1.82 (m, 2H), 1.61-1.48 (m, 2H), 1.15 (t, J=7.0 Hz, 3H) ppm.

Step 3: ethyl1-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)cyclopropanecarboxylate

To a solution of ethyl1-(8-chloroimidazo[1,5-a]pyrazin-3-yl)cyclopropanecarboxylate (60 mg,0.226 mmol) in MeCN (8 mL) was added NBS (48.2 mg, 0.271 mmol) and thereaction was stirred at 20° C. for 1 hour. The solution was quenchedwith Na₂SO₃ aqueous and the mixture was extracted with EtOAc (20 mL×2).The combined organic layers were washed with water, dried over Na₂SO₄and concentrated in vacuo to give the title compound. MS: 332/334 (M+1).

Step 4: ethyl1-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)cyclopropanecarboxylate

A solution of ethyl1-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)cyclopropanecarboxylate(78 mg, 0.226 mmol) in ammonia/propan-2-ol (15 mL, 60.0 mmol, 4M) wasstirred at 100° C. for 16 hours. Then the mixture was concentrated invacuo. The residue was dissolved in EtOAc (25 mL), washed with water.The combined organic layers were dried over Na₂SO₄ and concentrated invacuo to give the title compound. MS: 311/313 (M+1).

Intermediate 4

Methyl4-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)bicyclo[2.2.1]heptane-1-carboxylateStep 1: dimethyl bicyclo[2.2.1]heptane-1,4-dicarboxylate

To a solution of HMPA (13.08 mL, 75 mmol) and LDA (13.43 mL, 26.9 mmol)in THF (30 mL) was added a solution of dimethylcyclopentane-1,3-dicarboxylate (2 g, 10.74 mmol) in 10 mL THF dropwiseover 30 minutes at −78° C. under N₂ protection and stirred at one pointfor another 30 minutes. The solution was warmed to 0° C. and stirred atone point for 1 hour. The solution was cooled to −78° C. and added asolution of 1-bromo-2-chloroethane (1.848 g, 12.89 mmol) in 10 mL THFdropwise. The solution was stirred at −78° C. for 1 hour and warmed toRT. After stirred for 16 hours, the solution was added 1N HCl andextracted with EtOAc. The combined organic layer was dried over Na₂SO₄,concentrated in vacuo to give the title compound. ¹H NMR (CDCl₃ 400MHz): δ 3.67 (s, 6H), 2.01 (d, J=6.7 Hz, 4H), 1.89 (s, 2H), 1.66 (d,J=6.7 Hz, 3H) ppm.

Step 2: bicyclo[2.2.1]heptane-1,4-dicarboxylic acid

A solution of dimethyl bicyclo[2.2.1]heptane-1,4-dicarboxylate (500 mg,2.356 mmol) and LiOH (169 mg, 7.07 mmol) in water (20 mL) and MeOH (10mL) was stirred at RT for 48 hours. The solution was poured into 1 N HCland extracted with EtOAc. The combined organic was dried over Na₂SO₄ andconcentrated in vacuo to give crude title compound.

Step 3: methyl4-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[2.2.1]heptane-1-carboxylate

To a solution of DMF (0.1 mL, 1.291 mmol) andbicyclo[2.2.1]heptane-1,4-dicarboxylic acid (450 mg, 2.443 mmol) in DCM(20 mL) was added oxalyl chloride (0.732 mL, 8.36 mmol) dropwise. Themixture was stirred at RT for 16 hours. The solution was concentrated invacuo and dissolved in MeCN. To the solution was added a solution of(3-chloropyrazin-2-yl)methanamine (200 mg, 1.393 mmol) and TEA (1.942mL, 13.93 mmol) in MeCN (100 mL) dropwise over 6 hours at 0° C. Thesolution was stirred at RT for another 1 hour and added MeOH (20.00 mL).The solution was stirred for 16 hours and added(diazomethyl)trimethylsilane (13.93 mL, 13.93 mmol). The solution wasstirred for another 4 hours and added 30 mL 1N HCl. The solution wasextracted with EtOAc and washed with water, brine, dried over Na₂SO₄ andpurified by chromatography over silica gel to give the title compound.MS: 324/326 (M+1).

Step 4: methyl4-(8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[2.2.1]heptane-1-carboxylate

A solution of methyl4-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[2.2.1]heptane-1-carboxylate (55 mg, 0.170 mmol) and pentachlorophosphorane(70.7 mg, 0.340 mmol) in MeCN (10 mL) was stirred at RT for 3 hours. Themixture was poured into 5% NaHCO₃ and extracted with EtOAc. The combinedorganic was washed with NaHCO₃ and water, dried over Na₂CO₃,concentrated in vacuo to give the title compound.

Step 5: methyl4-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[2.2.1]heptane-1-carboxylate

A solution of methyl4-(8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[2.2.1]heptane-1-carboxylate(48 mg, 0.157 mmol) and NBS (27.9 mg, 0.157 mmol) in MeCN (15 mL) wasstirred at RT for 1 hour. The solution was added 20 mL EtOAc and washedwith NH₄Cl, dried over Na₂SO₄ and concentrated in vacuo to give thetitle compound. MS: 384/386 (M+1).

Step 5: methyl4-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)bicyclo[2.2.1]heptane-1-carboxylate

A solution methyl 4-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[2.2.1] heptane-1-carboxylate (60 mg, 0.156 mmol) in ammonia,propan-2-ol (20 mL, 80 mmol) was stirred at 95° C. for 16 hours. Thesolution was concentrated in vacuo and dissolved in 20 mL EtOAc. Thesolution was washed with water, dried over Na₂SO₄ and concentrated invacuo to give the title compound. MS: 365/367 (M+1).

Intermediate 5

methyl4-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)bicyclo[2.2.2]octane-1-carboxylate

Intermediate 5 was prepared in the same procedure as intermediate 4using 4-(methoxycarbonyl)bicyclo[2.2.2]octane-1-carboxylic acid as thestarting material for step 1 to provide the title product methyl4-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)bicyclo[2.2.2]octane-1-carboxylate.LC-MS: (M+1)⁺ 381.0, Retention time=1.20 min (Method D).

Intermediate 6

ethyl4-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)tetrahydro-2H-pyran-4-carboxylateStep 1: 4-(ethoxycarbonyl)tetrahydro-2H-pyran-4-carboxylic acid

To a solution of diethyl dihydro-2H-pyran-4,4(3H)-dicarboxylate (900 mg,3.9 mmol) in EtOH (30 mL) was added NaOH aqueous (3.9 mL, 1 mol/L). Thereaction was stirred at 20° C. for 18 hours, then it was concentrated invacuum. The residue was diluted in water and acidified to pH=6. Themixture was extracted with EtOAc (40 mL). The organic layer was washedwith brine (20 mL×2), dried over with Na₂SO₄, concentrated under vacuumto give the title compound, which was used directly for the next step.

Step 2: ethyl4-(((3-chloropyrazin-2-yl)methyl)carbamoyl)tetrahydro-2H-pyran-4-carboxylate

To a solution of 4-(ethoxycarbonyl)tetrahydro-2H-pyran-4-carboxylic acid(600 mg, 2.97 mmol) and DIEA (1.14 mg, 3.9 mmol) in THF (20 mL) wasadded HATU (1.12 g, 2.97 mmol) at 20° C., then(3-chloropyrazin-2-yl)methanamine (510 mg, 3.56 mmol) was added. Themixture was concentrated under vacuum, and the residue was purified withsilica gel column chromatography (20 g, Pet.Ether:EtOAc=70:30) to givethe title compound. MS: 328.1 (M+1).

Step 3: ethyl4-(8-chloroimidazo[1,5-a]pyrazin-3-yl)tetrahydro-2H-pyran-4-carboxylate

To a solution of ethyl4-(((3-chloropyrazin-2-yl)methyl)carbamoyl)tetrahydro-2H-pyran-4-carboxylate(239 mg 0.95 mmol) in ACN (20 mL) was added PCl₅ (600 mg 2.88 mmol). Thereaction mixture was stirred at 60° C. for 2 hours. The mixture waspoured into sat. NaHCO₃ aqueous, then it was extracted with EtOAc (30mL×3), the organic layer was washed with brine (20 mL×2), dried overwith Na₂SO₄, concentrated in vacuum to give the crude title compound.MS: 310.1 (M+1).

Step 4: ethyl4-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)tetrahydro-2H-pyran-4-carboxylate

To a solution of ethyl4-(8-chloroimidazo[1,5-a]pyrazin-3-yl)tetrahydro-2H-pyran-4-carboxylate(336 mg 1.09 mmol) in ACN (20 mL) was added NBS (193 mg, 1.09 mmol). Thereaction was stirred at 20° C. for 2 hours. The mixture was poured intosat. Na₂SO₃ aqueous, then it was extracted with EtOAc (30 mL×2), theorganic layer was washed with brine (20 mL×2), dried over with Na₂SO₄,concentrated in vacuum to give the title compound. MS: 390.0 (M+1).

Step 5: ethyl4-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)tetrahydro-2H-pyran-4-carboxylate

The compound ethyl4-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)tetrahydro-2H-pyran-4-carboxylate(370 mg, 0.96 mmol) was added in NH₃/i-PrOH (20 mL, 4M). The mixture wasstirred at 100° C. for 15 hours under sealed tube. Then the reaction wasquenched with water (30 mL). The mixture was extracted by EtOAc (30mL×2), the organic layer was washed with brine (20 mL×2), dried overwith Na₂SO₄, concentrated under vacuum to give the title compound. MS:369.0/371.0 (M+1).

Intermediate 7

ethyl5-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.2.2]nonane-1-carboxylateStep 1:5-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.2.2]nonane-1-carboxylicacid

To a mixture of bicyclo[3.2.2]nonane-1,5-dicarboxylic acid (200 mg,0.942 mmol) and TEA (0.328 ml, 2.356 mmol) in THF (10 ml) was added HATU(340 mg, 0.895 mmol) at 0° C. The mixture was stirred at thistemperature for 10 mins and at 25° C. for another 20 mins.(3-chloropyrazin-2-yl)methanamine hydrochloride (170 mg, 0.942 mmol) wasadded to above solution at 0° C. and the mixture was allowed to warm toroom temperature. The mixture was stirred at room temperature for 30mins. The mixture was treated with water (20 mL) and EA (20 mL). The EAlayer was separated and was washed with brine (20 mL), dried overNa₂SO₄, filtered and concentrated. The residue was used next stepwithout further purification.

Step 2: ethyl5-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.2.2]nonane-1-carboxylate

To a solution of5-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.2.2]nonane-1-carboxylicacid (478 mg, 1.415 mmol) and K₂CO₃ (489 mg, 3.54 mmol) in DMF (20 ml)was added iodomethane (0.137 ml, 1.698 mmol) at 25° C. The mixture wasstirred at this temperature for 2 hours. TLC showed the reaction wascompleted. The mixture was treated with EA (40 mL) and water 20 (mL).The EA layer was separated and was washed with water three times (3×20mL), brine (20 mL), dried over Na₂SO₄. The mixture was filtered and thefiltrate was concentrated. The residue was purified by silica gel columnchromatography (PE/THF=5/1) to afford the product compound ethyl5-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.2.2]nonane-1-carboxylateas solid.

Step 3: ethyl5-(8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.2.2]nonane-1-carboxylate

A mixture of ethyl5-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.2.2]nonane-1-carboxylate(430 mg, 1.175 mmol) and PC15 (1224 mg, 5.88 mmol) in MeCN (20 ml) wasstirred at 60° C. for 2 hours. The mixture was quenched with saturatedNaHCO₃ and extracted with EA. The EA layer was washed with brine anddried over anhydrous Na₂SO₄. The mixture was filtered and the filtratewas concentrated. The residue was purified by silica gel columnchromatography (PE/THF=3/1) to afford the product compound ethyl5-(8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.2.2]nonane-1-carboxylate.

Step 4: ethyl 5-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.2.2]nonane-1-carboxylate

A mixture of ethyl5-(8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.2.2]nonane-1-carboxylate(240 mg, 0.690 mmol) and NBS (123 mg, 0.690 mmol) in MeCN (20 mL) wasstirred at 25° C. for 30 mins. The mixture was treated with water (20mL) and EA (20 mL). The EA layer was separated and was washed withwater, brine, dried over Na₂SO₄, filtered and concentrated in vacuo. Theresidue was purified by silica gel column chromatography (PE/THF=3/1) toafford ethyl5-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.2.2]nonane-1-carboxylate.

Step 5: ethyl5-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.2.2]nonane-1-carboxylate

A solution of ethyl5-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.2.2]nonane-1-carboxylate(35 mg, 0.082 mmol) in 10 ml 4N NH3/i-PrOH was stirred at 90° C. for 16hours. The mixture was filtered and the filtrate was concentrated. Theresidue was purified by silica gel column chromatography (PE/THF1/1) toafford the product compound ethyl5-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.2.2]nonane-1-carboxylate.

Intermediate 8

(1S,3R)-methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1,2,2-trimethylcyclopentanecarboxylateStep 1: (1S,3R)-dimethyl 1,2,2-trimethylcyclopentane-1,3-dicarboxylate

To a suspension of (1S,3R)-1,2,2-trimethylcyclopentane-1,3-dicarboxylicacid (4.87 g, 24.32 mmol) and K₂CO₃ (10.08 g, 73.0 mmol) in DMF (50 mL)was stirred at 13° C. and iodomethane (12.62 g, 89 mmol) was added. Thenthe mixture was stirred at 13° C. for 3 h. The reaction mixture wasadded EtOAc (100 mL) and washed with water and brine, dried over Na₂SO₄and concentrated to give the title compound. ¹H NMR (400 MHz, MeOH-d4):δ3.66 (d, J=3.9 Hz, 6H), 2.87 (t, J=9.4 Hz, 1H), 2.54 (dt, J=7.6, 12.6Hz, 1H), 2.21-2.08 (m, 1H), 1.90-1.76 (m, 1H), 1.50 (ddd, J=3.9, 9.6,13.5 Hz, 1H), 1.22 (d, J=12.5 Hz, 6H), 0.73 (s, 3H) ppm.

Step 2:(1S,3R)-3-(methoxycarbonyl)-2,2,3-trimethylcyclopentanecarboxylic acid

To a solution of (1S,3R)-dimethyl1,2,2-trimethylcyclopentane-1,3-dicarboxylate (5.37 g, 23.52 mmol) andlithium hydroxide hydrate (0.987 g, 23.52 mmol) in MeOH (60 mL) wasstirred at 10° C. for 40 h. It was no reaction detected by TLC. Themixture was concentrated to remove MeOH (20 mL), and then 5 mL of waterwas added and stirred at 30° C. for overnight. The reaction wasincomplete detected by TLC. The mixture was heated to 50° C. forovernight. The reaction was complete detected by TLC. The mixture wasconcentrated to remove solvent, and then added water (100 mL), washedwith EtOAc. The water layer was added HCl to adjust to pH=3, and thenthe mixture was extracted with EtOAc (3×30 mL), the organic layer wasdried over Na₂SO₄ and concentrated to give the title compound. ¹H NMR(400 MHz, CDCl₃): δ 3.69 (s, 3H), 2.84 (t, J=9.4 Hz, 1H), 2.59 (dt,J=7.6, 12.6 Hz, 1H), 2.22-2.12 (m, 1H), 1.90-1.78 (m, 1H), 1.53 (ddd,J=3.9, 9.6, 13.5 Hz, 1H), 1.33-1.26 (m, 3H), 1.22 (s, 3H), 0.85 (s, 3H)ppm.

Step 2: (1S,3R)-methyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-1,2,2-trimethylcyclopentanecarboxylate

To a mixture of(1S,3R)-3-(methoxycarbonyl)-2,2,3-trimethylcyclopentanecarboxylic acid(4.93 g, 23.01 mmol) and TEA (9.62 mL, 69.0 mmol) and HATU (13.12 g,34.5 mmol) in DCM (100 mL) was stirred at 12° C. for 30 min.(3-chloropyrazin-2-yl) methanamine hydrochloride (4.97 g, 27.6 mmol) wasadded and the mixture was stirred at 12° C. for overnight. The mixturewas added DCM (100 mL) and washed and brine. The organic layer was driedover Na₂SO₄, purified with silica gel to give the title compound. ¹H NMR(400 MHz, CDCl₃): δ 8.46 (d, J=2.3 Hz, 1H), 8.34 (s, 1H), 6.70 (br. s.,1H), 4.81-4.66 (m, 2H), 3.69 (s, 3H), 2.74 (t, J=9.2 Hz, 1H), 2.65 (dt,J=6.8, 12.6 Hz, 1H), 2.34-2.22 (m, 1H), 1.91-1.80 (m, 1H), 1.54 (ddd,J=4.1, 9.6, 13.7 Hz, 1H), 1.32 (s, 3H), 1.25 (s, 3H), 0.81 (s, 3H) ppm.

Step 3: (1S,3R)-methyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-1,2,2-trimethylcyclopentanecarboxylate

(1S,3R)-methyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-1,2,2-trimethylcyclopentanecarboxylate(7.76 g, 22.84 mmol) was dissolved in acetonitrile (100 mL) and cooledto 0° C., PCl₅ (14.27 g, 68.5 mmol) was added slowly. The mixture wasstirred at room temperature for 30 min. The reaction was poured intosaturated sodium bicarbonate at 0° C. Then the mixture was extractedwith EtOAc, dried over anhydrous sodium sulfate and sodium carbonate,filtered and concentrated to give crude title compound.

Step 4: (1S,3R)-methyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-1,2,2-trimethylcyclopentanecarboxylate

NBS (4.28 g, 24.03 mmol) was added in portions to a stirred solution of(1S,3R)-methyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-1,2,2-trimethylcyclopentanecarboxylate (7.03 g, 21.85 mmol) in acetonitrile (80 mL). The mixturewas stirred at 12° C. for 1 h. The reaction was added saturated sodiumsulfite and extracted with EtOAc, the organic layer was dried overanhydrous sodium sulfate, purified with silica gel to give the titlecompound. ¹H NMR (400 MHz, CDCl₃): δ7.69 (d, J=4.7 Hz, 1H), 7.29 (d,J=5.1 Hz, 1H), 3.70 (s, 3H), 3.53 (t, J=9.4 Hz, 1H), 2.82 (dt, J=6.3,12.9 Hz, 1H), 2.70-2.59 (m, 1H), 2.15-2.06 (m, 1H), 1.67 (ddd, J=4.3,9.5, 13.6 Hz, 1H), 1.38 (s, 2H), 1.13 (s, 2H), 0.75 (s, 2H) ppm.

Step 5: (1S,3R)-methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1,2,2-trimethylcyclopentanecarboxylate

To a mixture of (1S, 3R)-methyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-1,2,2-trimethylcyclopentanecarboxylate(4 g, 9.98 mmol) and NH₃.H₂O (20 mL) in 2-propanol (20 mL) was stirredat 110° C. for overnight on a sealed tube. The reaction mixture wasconcentrated to remove solvent. And then the mixture was added water (50mL), extracted with EtOAc, The organic layer was purified with silicagel to give the title compound. ¹H NMR (400 MHz, CDCl₃): δ 7.27-7.26 (d,J=4 Hz, 1H), 7.01-7.00 (m, 1H), 5.73 (br. s., 2H), 3.69 (s, 3H), 3.49(t, J=9.8 Hz, 1H), 2.80 (dt, J=6.3, 12.7 Hz, 1H), 2.65-2.54 (m, 1H),2.11-1.99 (m, 1H), 1.64 (ddd, J=4.3, 9.7, 13.8 Hz, 1H), 1.36 (s, 3H),1.12 (s, 3H), 0.75 (s, 3H) ppm.

Intermediate 9

ethyl4-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2,2,5,5-tetrafluorobicyclo[2.2.2]octane-1-carboxylateStep 1: diethyl2,2,5,5-tetrafluorobicyclo[2.2.2]octane-1,4-dicarboxylate

A solution of diethyl bicyclo[2.2.2]octane-1,4-dicarboxylate (500 mg,1.75 mmol) in DCM (5 mL) was added DAST (704 mg, 4.37 mmol) at 0° C. Themixture was stirred at 0° C. for 1 hour. After the reaction, aq NaHCO₃was added to the mixture. The mixture was extracted by EA (10 mL). Theorganic layer was washed with H₂O (20 mL) and brine (20 mL), dried overNa₂SO₄, concentrated to afford the crude product, which was purified onsilica gel chromatography with the eluent of PE:THF (10:1-5:1) to givethe title compound.

¹H NMR (400 MHz, CDCl₃) δ=5.10-4.88 (m, 1H), 4.28-4.06 (m, 4H),2.72-2.58 (m, 1H), 2.40-2.22 (m, 2H), 2.18 (s, 2H), 2.16-2.09 (m, 1H),2.09-1.80 (m, 3H), 1.78-1.63 (m, 1H), 1.35-1.19 (m, 6H) ppm.

Step 2:2,2,5,5-tetrafluoro-4-(methoxycarbonyl)bicyclo[2.2.2]octane-1-carboxylicacid

A solution of diethyl2,2,5,5-tetrafluorobicyclo[2.2.2]octane-1,4-dicarboxylate (100 mg, 0.31mmol) in THF (2 mL) was added a solution of NaOH (12 mg, 0.3 mmol) inEtOH (2 mL) at 25° C. The mixture was stirred at 25° C. for 16 hours.After the reaction, HCl (0.5 mL, 2M) was added to the mixture. Themixture was extracted by EA (10 mL). The organic layer was washed withH₂O (20 mL) and brine (20 mL), dried over anhydrous Na₂SO₄, concentratedto afford the crude product of title compound as solid.

Step 3: methyl4-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-2,2,5,5-tetrafluorobicyclo[2.2.2]octane-1-carboxylate

A solution of2,2,5,5-tetrafluoro-4-(methoxycarbonyl)bicyclo[2.2.2]octane-1-carboxylicacid (70 mg, 0.23 mmol) in DCM (2 mL) was added (CClO)₂ (42 mg, 0.33mmol) at 0° C., the mixture was stirred at 25° C. for 1 hour. Themixture was concentrated in vacuo. The residue was dissolved in DCM (2mL). The solution was added into a solution of (3-chloropyrazin-2-yl)methanamine (27 mg, 0.18 mmol) and Et₃N (0.075 mL, 0.54 mmol) in 1 mL ofDCM at 0° C. And the mixture was stirred at 25° C. for 1 hour. H₂O (20mL) was added to the mixture, the mixture was extracted by EA (10 mL).The organic layer was washed with H₂O (10 mL) and brine (10 mL), driedover Na₂SO₄, concentrated to afford the crude product, which waspurified on silica gel chromatography with the eluent of PE:THF(5:1-1:1) to give the title compound as a solid. ¹H NMR (400 MHz, CDCl₃)δ=8.45 (br. s., 1H), 8.37-8.27 (m, 1H), 7.49 (br. s., 1H), 7.34-7.26 (m,1H), 4.81-4.62 (m, 2H), 3.87-3.73 (m, 3H), 2.79-2.59 (m, 2H), 2.54-2.31(m, 3H), 2.21-1.93 (m, 2H), 1.88-1.72 (m, 1H) ppm.

Step 4: methyl4-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-2,2,5,5-tetrafluorobicyclo[2.2.2]octane-1-carboxylate

A solution of methyl4-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-2,2,5,5-tetrafluorobicyclo[2.2.2]octane-1-carboxylate(200 mg, 0.48 mmol) in MeCN (3 mL) was added PCl₅ (500 mg, 2.44 mmol) at0° C. under nitrogen, the mixture was stirred at 80° C. for 16 hours.The solution was added to aq NaHCO₃ at 0° C., and the mixture wasextracted by DCM (20 mL). The organic layer was washed with H₂O (30 mL)and brine (30 mL), dried over Na₂SO₄, concentrated to afford the crudeproduct which was purified on silica gel chromatography with the eluentof PE:THF (5:1-1:1) to give methyl4-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-2,2,5,5-tetrafluorobicyclo[2.2.2]octane-1-carboxylate.¹H NMR (400 MHz, CDCl₃) δ=8.45 (d, J=2.0 Hz, 1H), 8.31 (br. s., 1H),7.98 (d, J=4.7 Hz, 1H), 7.31 (d, J=5.1 Hz, 1H), 3.86 (s, 2H), 3.83-3.76(m, 3H), 3.19-3.03 (m, 1H), 2.83-2.69 (m, 4H), 2.64-2.43 (m, 4H),2.02-1.88 (m, 2H) ppm.

Step 5: ethyl4-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-2,2,5,5-tetrafluorobicyclo[2.2.2]octane-1-carboxylate

A solution of methyl4-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-2,2,5,5-tetrafluorobicyclo[2.2.2]octane-1-carboxylate(80 mg, 0.2 mmol) in MeCN (5 mL) was added NBS (47 mg, 2.36 mmol) at 20°C. under nitrogen. The mixture was stirred at 25° C. for 1 hour. H₂O (10mL) was added to the mixture, the mixture was extracted by EA (10 mL).The organic layer was washed with H₂O (20 mL) and brine (20 mL), driedover Na₂SO₄, concentrated to afford the crude product of ethyl4-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-2,2,5,5-tetrafluorobicyclo[2.2.2]octane-1-carboxylate.MS: 472.0 (M+1)

Step 6: ethyl4-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2,2,5,5-tetrafluorobicyclo[2.2.2]octane-1-carboxylate

A solution of ethyl4-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-2,2,5,5-tetrafluorobicyclo[2.2.2]octane-1-carboxylate(120 mg, 0.25 mmol) in i-PrOH (4 mL) was added NH₃H₂O (4 mL) at 25° C.The mixture was stirred at 100° C. for 16 hours in sealed tube. Afterthe reaction mixture cooled, the mixture was concentrated to afford thecrude product of title compound as solid. MS: 464.0 (M+1).

Intermediate 10

7-(8-Amino-1-bromo-imidazo[1,5-a]pyrazin-3-yl)-3-methyl-hexahydro-pyrido[2,1-c][1,4]oxazin-4-oneStep 1: dimethyl 1,4-dimethylcyclohexane-1,4-dicarboxylate

To a solution of LDA (125 mL, 250 mmol) and HMPA (139 mL, 799 mmol) inTHF (250 mL) was added a solution of dimethylcyclohexane-1,4-dicarboxylate (20 g, 100 mmol) in 20 mL THF dropwise at−78° C. under N₂ and stirred at −78° C. for 1 hour. The solution stirredat 0° C. for 1 hour. To the solution was added MeI (77.49 g, 546 mmol)at −78° C. and stirred at RT for 1 hour. The solution was added 1N HCl(30 mL) and extracted with EtOAc. The combined organic layers were driedover Na₂SO₄ and purified by chromatography on silica gel to give thetitle compound. ¹H NMR (400 MHz, CDCl₃) δ=3.69 (s, 6H), 2.13-2.02 (m,4H), 1.26-1.19 (m, 4H), 1.13 (s, 6H) ppm.

Step 2: 4-(methoxycarbonyl)-1,4-dimethylcyclohexanecarboxylic acid

A solution of dimethyl 1,4-dimethylcyclohexane-1,4-dicarboxylate (900mg, 3.94 mmol) and KOH (265 mg, 4.73 mmol) in MeOH (15 mL) and water (15mL) was stirred at 80° C. for 16 hours. The solution was concentrated invacuo and added 1N HCl and extracted with EtOAc. The combined organiclayers were dried over Na₂SO₄ and concentrated in vacuo to give thecrude title compound.

Step 3: (3R,6S)-methyl1-((R)-2-chloropropanoyl)-6-(hydroxymethyl)piperidine-3-carboxylate

To a solution of DMF (0.1 mL, 1.291 mmol) and4-(methoxycarbonyl)-1,4-dimethyl cyclohexanecarboxylic acid (845 mg,3.94 mmol) in DCM (30 mL) was added (COCl)₂ (0.690 mL, 7.89 mmol)dropwise and stirred at room temperature for 16 hours. The solution wasconcentrated in vacuo and dissolved in MeCN (15 mL). To the solution wasadded a solution of methyl4-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1,4-dimethylcyclohexanecarboxylate (852 mg, 4.73 mmol) and TEA (5.50 mL, 39.4 mmol)in 50 mL MeCN dropwise over 6 hours at 0° C. The solution was stirred atroom temperature for another 1 hour and added MeOH (15 mL). The solutionwas stirred for 16 hours and added 30 mL 1N HCl. The solution wasextracted with EtOAc and washed with water, brine, dried over Na₂SO₄ andpurified by chromatography over silica gel (12 g) to give the titlecompound. ¹H NMR (CDCl₃ 400 MHz) δ 8.46 (d, J=2.5 Hz, 1H), 8.33 (s, 1H),7.01 (br. s., 1H), 4.71 (d, J=4.5 Hz, 2H), 3.70 (s, 3H), 2.13-2.05 (m,4H), 1.43-1.31 (m, 4H), 1.18 (s, 3H), 1.14 (s, 3H) ppm.

Step 4: methyl4-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-1,4-dimethylcyclohexanecarboxylate

A solution of methyl4-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-1,4-dimethylcyclohexanecarboxylate (1 g, 2.94 mmol) and PCl₅ (0.919 g, 4.41 mmol) inMeCN (20 mL) was stirred at RT for 2 hours. The solution was poured into5% NaHCO₃ and extracted with EtOAc. The combined organic was dried overK₂CO₃ and concentrated in vacuo to give the crude title compound.

Step 5: methyl4-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-1,4-dimethylcyclohexanecarboxylate

A mixture of methyl4-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-1,4-dimethylcyclohexanecarboxylate (0.95 g, 2.95 mmol) in MeCN (30 mL) was added NBS (0.788 g,4.43 mmol) and stirred at room temperature for 2 hours. The mixture wasadded 30 mL EtOAc, washed with Na₂SO₃, dried over Na₂SO₄, concentratedin vacuo and purified by chromatography over silica gel (20 g) to givethe title compound. MS: 402 (M+1).

Step 6: methyl4-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1,4-dimethylcyclohexanecarboxylate

A solution of methyl4-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-1,4-dimethylcyclohexanecarboxylate (650 mg, 1.622 mmol) in ammonia, propan-2-ol (25mL, 100 mmol) was stirred at 100° C. for 16 hours. The solution wasconcentrated in vacuo to give the title compound. MS: 381/383 (M+1).

Intermediate 11

trans-methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1,3-dimethylcyclopentanecarboxylateStep 1: trans-dimethyl 1,3-dimethylcyclopentane-1,3-dicarboxylate

To a solution of dimethyl cyclopentane-1,3-dicarboxylate (10 g, 53.7mmol) in THF (20 mL) was added a solution of MeI (41.0 mL, 655 mmol) in10 mL toluene under N₂ protection dropwise at −78° C. and stirred at−78° C. for 25 minutes. To the solution was added a solution of LDA (161mL, 322 mmol) in 10 mL toluene dropwise and stirred at room temperaturefor another 16 hours. The solution was poured into water and extractedwith EtOAc. The combined organic layers were washed with water andbrine, dried over Na₂SO₄, concentrated in vacuo and purified bychromatography over silica gel (120 g) to give the title compound. ¹HNMR (trans) (400 MHz, CDCl₃): δ3.69 (s, 6H), 2.29-2.20 (m, 2H), 2.15 (s,2H), 1.65-1.57 (m, 2H), 1.34-1.21 (m, 6H) ppm. ¹H NMR (cis) (400 MHz,CDCl₃): δ3.70-3.60 (m, 6H), 2.85 (d, J=14.1 Hz, 1H), 2.32-2.20 (m, 2H),1.61-1.52 (m, 2H), 1.32-1.24 (m, 6H) ppm.

Step 2: trans-1,3-dimethylcyclopentane-1,3-dicarboxylic acid

A solution of compound trans-dimethyl1,3-dimethylcyclopentane-1,3-dicarboxylate (950 mg, 4.43 mmol) and LiOH(319 mg, 13.30 mmol) in water (10 mL) and MeOH (10 mL) was stirred atr.t. for 48 hours. The solution was poured into 1 N HCl and extractedwith EtOAc. The combined organic layers were dried over Na₂SO₄ andconcentrated in vacuo to give the crude title compound. ¹H NMR (DMSO-d6400 MHz): δ 12.14 (br. s., 4H), 2.17-2.05 (m, 2H), 1.98 (s, 2H),1.55-1.39 (m, 2H), 1.23-1.11 (m, 6H) ppm.

Step 3: trans-methyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-1,3-dimethylcyclopentanecarboxylate

To a solution of DMF (0.1 mL, 1.291 mmol) andtrans-1,3-dimethylcyclopentane-1,3-dicarboxylic acid (500 mg, 2.69 mmol)in DCM (20 mL) was added oxalyl dichloride (796 mg, 6.27 mmol) dropwiseand stirred at room temperature for 16 hours. The solution wasconcentrated in vacuo and dissolved in DCM (20 mL). To the solution wasadded a solution of TEA (1.4 mL, 10.03 mmol) and(3-chloropyrazin-2-yl)methanamine (180 mg, 1.254 mmol) in 100 mL MeCNdropwise over 6 hours at 0° C. The solution was stirred at ROOMTEMPERATURE for another 1 hour and added MeOH (20 mL). The solution wasstirred for 16 hours and added (diazomethyl)trimethylsilane (7.52 mL,7.52 mmol). The solution was stirred for another 4 hours and added 30 mL1N HCl. The solution was extracted with EtOAc and washed with water,brine, dried over Na₂SO₄ and purified by chromatography over silica gel(12 g) to give the title compound.

Step 4: trans-ethyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-1,3-dimethylcyclopentanecarboxylate

A solution of pentachlorophosphorane (479 mg, 2.302 mmol) and compoundtrans-methyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-1,3-dimethylcyclopentanecarboxylate (250 mg, 0.767 mmol) in MeCN (30 mL) was stirred at 80° C.for 2 hours. The mixture was poured into 10% NaHCO₃ and extracted withEtOAc. The combined organic layer was washed with NaHCO₃ and water,dried over Na₂SO₄ and concentrated in vacuo to give the crude titlecompound.

Step 5:trans-ethyl-3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-3-dimethylcyclo pentanecarboxylate

To a solution of methyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-1,3-dimethylcyclopentanecarboxylate(240 mg, 0.780 mmol) in MeCN (20 mL) was added NBS (139 mg, 0.780 mmol)and stirred for 1 hour. The solution was added 30% NH₄Cl and extractedwith EtOAc. The combined organic was washed with water, dried overNa₂SO₄ and concentrated in vacuo to give the crude title compound. MS:388 (M+1).

Step 6: trans-methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1,3-dimethyl cyclopentanecarboxylate

A solution of compound trans-methyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-1,3-dimethylcyclopentanecarboxylate(302 mg, 0.781 mmol) in AMMONIA (30 mL, 388 mmol) and i-PrOH (5 mL, 64.9mmol) was stirred at 100° C. for 16 hours. The solution was extractedwith EtOAc. The combined organic was washed with water, dried overNa₂SO₄ and concentrated in vacuo to give the title compound. MS: 367/369(M+1).

Intermediate 12

3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1,3-dimethylcyclopentanecarboxylicacid Step 1: dimethyl cyclopentane-1,3-dicarboxylate

Oxalyl dichloride (10.03 g, 79 mmol) was added to a solution ofcyclopentane-1,3-dicarboxylic acid (5 g, 31.6 mmol) in dry MeOH (50 mL)under argon in an ice-water bath. The solution was allowed to warm toroom temperature and stirred overnight. Volatiles were then removedunder vacuum. The residue was taken up in EtOAc (2×50 mL) and thesolution was washed with NaHCO₃ (2×50 mL) and brine (50 mL), dried overMgSO₄, filtered, and concentrated to give the title compound. ¹H NMR(400 MHz, CDCl₃): δ3.70 (s, 6H), 2.75-2.90 (m, 2H), 2.20-2.30 (m, 1H),2.10-2.20 (m, 1H), 1.90-2.20 (m, 4H).

Step 2: dimethyl 1,3-dimethylcyclopentane-1,3-dicarboxylate

To a solution a solution of LDA (33.6 mL, 67.1 mmol) in 10 mL THF wasadded a solution of dimethyl cyclopentane-1,3-dicarboxylate (5 g, 26.9mmol) in 10 mL THF under N₂ protection dropwise at −78° C. and stirredat −78° C. for 25 minutes. To the solution was added iodomethane (9.53g, 67.1 mmol) dropwise and stirred at ROOM TEMPERATURE for another 16hours. The solution was poured into water and extracted with EtOAc. Thecombined organic layers were washed with water and brine, dried overNa₂SO₄, concentrated in vacuo to give the title compound. ¹H NMR (400MHz, CDCl₃): δ3.66 (major), 3.63 (minor) (s, 6H), 2.29-2.20 (m, 2H),2.12 (s, 2H), 1.65-1.55 (m, 2H), 1.30-1.20 (m, 6H) ppm.

Step 3: 3-(methoxycarbonyl)-1,3-dimethylcyclopentanecarboxylic acid

A solution of KOH (1.309 g, 23.34 mmol) in methanol (20.0 mL) was addedslowly over a period of 1.5 h to a refluxing solution of dimethyl1,3-dimethylcyclopentane-1,3-dicarboxylate (5 g, 23.34 mmol) in methanol(30 mL). The mixture was kept refluxing for 1 h. The solvent was removedin vacuo, and the remaining oil was dissolved in water (40 mL). Thesolution was acidified with dilute HCl to pH 1. The mixture wasextracted with dichloromethane (3×50 mL). The combined organic layerswere concentrated to give the crude title compound. ¹H NMR (400 MHz,CDCl₃): δ 3.66 (major), 3.63 (minor) (s, 6H), 2.18-2.30 (m, 2H), 2.14(major), 2.11 (minor) (s, 2H), 1.50-1.70 (m, 2H), 1.24-1.28 (m, 6H) ppm.

Step 4: methyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-1,3-dimethylcyclopentanecarboxylate

To a stirred solution of3-(methoxycarbonyl)-1,3-dimethylcyclopentanecarboxylic acid (4 g, 19.98mmol) in DMF (30 mL) was added HATU (11.39 g, 30.0 mmol) andN-ethyl-N-methylethanamine (3.48 g, 40.0 mmol). The solution was stirredat room temperature for 30 minutes. Then to this solution was added(3-chloropyrazin-2-yl)methanamine (3.44 g, 23.97 mmol). The mixture wasstirred at room temperature overnight. The reaction mixture was purifiedby chromatography (petroleum ether: ethyl acetate=1:1) to give the titlecompound. MS: 326 (M+1).

Step 5: methyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-1,3-dimethylcyclopentanecarboxylate

A solution of methyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-1,3-dimethylcyclopentanecarboxylate(3 g, 9.21 mmol) and PCl₅ (5.75 g, 27.6 mmol) in acetonitrile (10 mL)was stirred at 80° C. for 2 hours and poured into 10% NaHCO₃. Themixture was washed with EtOAc. The combined organic was dried over K₂CO₃and concentrated in vacuo. The residue was purified by columnchromatography (petroleum ether: ethyl acetate=1:1) to give the crudetitle compound.

Step 6: methyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-1,3-dimethylcyclopentanecarboxylate

To a solution of methyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-1,3-dimethylcyclopentanecarboxylate(200 mg, 0.650 mmol) in MeCN (10 mL) was added1-bromopyrrolidine-2,5-dione (116 mg, 0.650 mmol) and stirred for 1hour. The solution was added 30% NH₄Cl and extracted with EtOAc. Thecombined organic layers were washed with water, dried over Na₂SO₄ andconcentrated in vacuo to give crude title compound. MS: 387.9 (M+1).

Step 7: methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1,3-dimethylcyclopentanecarboxylate

A solution of methyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-1,3-dimethylcyclopentanecarboxylate (100 mg, 0.259 mmol), ammonia hydrate (1.5 mL,0.259 mmol) was added i-PrOH (1 mL). The reaction was stirred at 100° C.for 16 hours. The reaction mixture was concentrated in vacuo, dissolvedin EtOAc, washed with water. The combined organic layers were dried overNa₂SO₄ and concentrated in vacuo to give the title compound.

Step 8:3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1,3-dimethylcyclopentanecarboxylic acid

To a solution methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1,3-dimethylcyclopentanecarboxylate (200 mg, 0.545 mmol) in MeOH (10 mL) and water(5 mL) was added KOH (92 mg, 1.634 mmol). Then the reaction mixture wasstirred at 80° C. for 16 h. The resulting aqueous solution was washedwith EtOAc (50.0 mL), and then adjusted to pH=3.0 with HCl aqueous. Thecombined organic layers were dried over anhydrous Na₂SO₄, andconcentrated in vacuum to give the title compound. MS: 387.9 (M+1).

Intermediate 13A & 13B

(1S,3R)-methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclohexanecarboxylateand (1R,3S)-methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclohexanecarboxylateStep 1: dimethyl 1-isopropylcyclohexane-1,3-dicarboxylate

To a solution of dimethyl cyclohexane-1,3-dicarboxylate (5.2 g, 26 mmol)in THF (60 mL) was added HMPT (18.6 g, 104 mmol) followed by LDA (14.3mL, 28.6 mmol) at −70° C. The resulting mixture was stirred at −70° C.for 1 h. 2-iodopropane (8.8 g, 52 mmol) was then added dropwise, and themixture was allowed to warm to room temperature and stirred for further4 hrs. The mixture was quenched with saturated NH₄Cl solution andextracted with EA. The organic layer was dried and concentrated, theresidue was purified by column chromatography on silica gel eluted withPE/EA=10/1 to give dimethyl 1-isopropylcyclohexane-1,3-dicarboxylate assolid.

¹H NMR (400 MHz, CDCl₃) δ ppm: 0.88 (dd, J=6.65, 3.13 Hz, 6H), 1.10-1.33(m, 4H), 1.70-1.79 (m, 2H), 1.87-1.96 (m, 1H), 2.06-2.18 (m, 1H),2.29-2.49 (m, 2H), 3.68 (d, J=7.83 Hz, 6H).

Step 2: 3-isopropyl-3-(methoxycarbonyl)cyclohexanecarboxylic acid

To a solution of dimethyl 1-isopropylcyclohexane-1,3-dicarboxylate (4.5g, 18.6 mmol) in THF/MeOH/H₂O (30 mL/30 mL/10 mL) was added LiOH.H₂O(2.3 g, 55.8 mmol). The mixture was stirred at room temperature for 4hrs. The reaction mixture was acidified by 1 M HCl, and extracted withEA. The organic layer was dried and concentrated, and the residue wasused in next step directly.

Step 3: methyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-1-isopropylcyclohexanecarboxylate

To a solution of 3-isopropyl-3-(methoxycarbonyl)cyclohexanecarboxylicacid (4.4 g, 19.3 mmol) in THF (100 mL) was added(3-chloropyrazin-2-yl)methanamine hydrochloride (5.2 g, 28.9 mmol), HATU(11 g, 28.9 mmol) and TEA (11.7 g, 115.8 mmol). The mixture was stirredat room temperature overnight. The reaction mixture was diluted with EAand water, the organic layer was dried and concentrated. The residue waspurified by column chromatography on silica gel eluted with PE/THF=5/1to give methyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-1-isopropylcyclohexanecarboxylate.

¹H NMR (400 MHz, CDCl₃) δ ppm: 0.86 (t, J=6.65 Hz, 6H), 1.16-1.32 (m,2H), 1.36-1.47 (m, 2H), 1.69-1.87 (m, 3H), 2.07-2.16 (m, 1H), 2.22-2.42(m, 2H), 3.69 (s, 3H), 4.56-4.76 (m, 2H), 6.79 (s, 1H), 8.31 (d, J=2.74Hz, 1H), 8.45 (d, J=2.74 Hz, 1H).

Step 4: methyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclohexanecarboxylate

To a solution of methyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-1-isopropylcyclohexanecarboxylate(3 g, 8.5 mmol) in MeCN (80 mL) was added PCl₅ (3.5 g, 17 mmol). Themixture was stirred at 70° C. for 3 hrs. The reaction solution wasdiluted with DCM and aqueous NaHCO₃. The organic layer was dried andconcentrated. The residue was purified by column chromatography onsilica gel eluted with PE/THF=20/1 to methyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclohexanecarboxylate.MS=336 (M+1)⁺

Step 5: methyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclohexanecarboxylate

To a solution of methyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclohexanecarboxylate(2.6 g, 7.8 mmol) in MeCN (30 ml) was added a solution of NBS (1.5 g,8.5 mmol) in MeCN (10 ml). The mixture was stirred at room temperaturefor 1 hr.

The reaction mixture was treated with EA and water, the organic layerwas dried and concentrated. The residue was purified by columnchromatography on silica gel eluted with PE/THF=20/1 to give methyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclohexanecarboxylate.MS: 416 (M+1).

Step 6: (1S,3R)-methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclohexanecarboxylateand (1R,3S)-methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclohexanecarboxylate

In 100 mL seal tube, a solution of methyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclohexanecarboxylate(2 g, 4.8 mmol) in NH₃/i-PrOH (20 mL) was added, and the mixture wasstirred at 100° C. overnight. The reaction mixture was concentrated andthe residue was purified by column chromatography on silica gel elutedwith DCM/THF=20/1 to give methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclohexanecarboxylate.The product was separated by SFC to give (1S,3R)-methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclohexanecarboxylateand (1R,3S)-methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclohexanecarboxylate.

¹H NMR (400 MHz, CD₃OD) δ ppm 0.88 (dd, J=6.85, 2.54 Hz, 6H), 1.31-1.46(m, 3H), 1.61-1.96 (m, 4H), 2.16-2.36 (m, 2H), 3.05-3.17 (m, 1H), 3.77(s, 3H), 6.97 (d, J=8.0 Hz, 1H), 7.47 (d, J=8.0 Hz, 1H) ppm.

Intermediate 14

5-(8-amino-1-(2-ethoxy-4-((4-(trifluoromethyl)pyridin-2-yl)carbamoyl)phenyl)imidazo[1,5-a]pyrazin-3-yl)tricyclo[3.2.2.02,4]nonane-1-carboxylicacid Step 1: dimethyl bicyclo[2.2.2]oct-2-ene-1,4-dicarboxylate

To a solution of bicyclo[2.2.2]oct-2-ene-1,4-dicarboxylic acid (2 g,10.19 mmol) in MeOH (20 ml) was added SOCl₂ (2.98 ml, 40.8 mmol), thenthe mixture was stirred at 70° C. for 2 h. The mixture was cooled toroom temperature, adjusted to basic with aq. NaHCO₃ (ph=8) and extractedwith ethyl acetate (100 mL×3). The combined organic layers were washedwith brine (100 mL), dried over anhydrous sodium sulfate, concentratedto afford crude product which was purified on silica gel columnchromatograph (PE:EA=100%˜70%) to give title compound.

¹H NMR (400 MHz, CDCl₃) δ=6.51 (s, 2H), 3.76 (s, 6H), 1.93 (d, J=7.0 Hz,4H), 1.50 (d, J=7.0 Hz, 4H) ppm.

Step 2: dimethyl tricyclo[3.2.2.02,4]nonane-1,5-dicarboxylate

To a solution of dimethyl bicyclo[2.2.2]oct-2-ene-1,4-dicarboxylate (1g, 4.46 mmol) in CH₂Cl₂ (2 ml) added diethylzinc (22.30 ml, 22.30 mmol)at 0° C. under nitrogen protection. The mixture was stirred at 0° C. for15 mins, and a solution of diiodomethane (3.60 ml, 44.6 mmol) was added.The reaction mixture was stirred at 20° C. for 12 hours. The mixture wasdiluted with DCM (5 mL) and 1N HCl (10 mL), extracted with DCM (10mL×3). The combined organic layers were washed with brine (10 mL) driedover anhydrous sodium sulfate and evaporated to give title compound. ¹HNMR (400 MHz, CDCl₃) δ=3.70 (s, 5H), 1.95 (d, J=6.7 Hz, 2H), 1.82 (d,J=7.4 Hz, 2H), 1.58 (d, J=5.9 Hz, 4H), 1.33 (dd, J=3.5, 7.4 Hz, 2H),0.73-0.67 (m, 1H), 0.50 (q, J=7.4 Hz, 1H) ppm.

Step 3: 5-(methoxycarbonyl)tricyclo[3.2.2.02,4]nonane-1-carboxylic acid

To a solution of dimethyl tricyclo[3.2.2.02,4]nonane-1,5-dicarboxylate(800 mg, 3.36 mmol) in anhydrous THF (1 ml) was added a solution of NaOH(132 mg, 3.29 mmol) in MeOH (2 ml). The mixture was stirred at 15° C.for 12 hours. The mixture was adjusted acid to pH=2 with 2M HCl and themixture was extracted with EA (10 mL×3), the combined organic layerswere washed with brine (10 mL), dried over sodium sulfate, filtered andconcentrated to give5-(methoxycarbonyl)tricyclo[3.2.2.02,4]nonane-1-carboxylic acid. ¹H NMR(400 MHz, CDCl₃) δ=3.73-3.63 (m, 3H), 2.01-1.89 (m, 3H), 1.88-1.76 (m,2H), 1.67-1.48 (m, 4H), 1.41-1.27 (m, 2H), 0.74-0.64 (m, 1H), 0.56-0.44(m, 1H) ppm.

Step 4: methyl5-(((3-chloropyrazin-2-yl)methyl)carbamoyl)tricyclo[3.2.2.02,4]nonane-1-carboxylate

To a solution of5-(methoxycarbonyl)tricyclo[3.2.2.02,4]nonane-1-carboxylic acid (440 mg,1.962 mmol) in anhydrous CH₂Cl₂ (8 ml) was added Et₃N (0.820 ml, 5.89mmol), (3-chloropyrazin-2-yl)methanamine, HCl (424 mg, 2.354 mmol) andHATU (895 mg, 2.354 mmol). The reaction mixture was stirred at 15° C.for 12 hours. The reaction was quenched by the addition of water (10mL), then it was extracted with DCM (20 mL×3), the combined organiclayers were washed with brine (20 mL), dried over sodium sulfate,filtered and concentrated to afford the crude product, which waspurified on silica gel column chromatograph (PE/EA=100%˜50%) to givemethyl5-(((3-chloropyrazin-2-yl)methyl)carbamoyl)tricyclo[3.2.2.02,4]nonane-1-carboxylate.¹H NMR (400 MHz, CDCl₃) δ=8.47 (d, J=2.5 Hz, 1H), 8.33 (s, 1H), 4.70 (d,J=4.8 Hz, 2H), 3.72 (s, 3H), 2.08-1.83 (m, 4H), 1.68-1.59 (m, 4H), 1.42(br. s., 1H), 1.25 (d, J=7.3 Hz, 1H), 0.84-0.78 (m, 1H), 0.68-0.61 (m,1H) ppm.

Step 5: methyl5-(8-chloroimidazo[1,5-a]pyrazin-3-yl)tricyclo[3.2.2.02,4]nonane-1-carboxylate

To a solution of methyl5-(((3-chloropyrazin-2-yl)methyl)carbamoyl)tricyclo[3.2.2.02,4]nonane-1-carboxylate(550 mg, 1.572 mmol) in MeCN (5 ml) was added pentachlorophosphorane(655 mg, 3.14 mmol) at 0° C. The mixture was allowed to warm to 10° C.and for 4 hours. The mixture was added to Sat. NH₄Cl (20 mL) dropwise at0° C. and extracted with ethyl acetate (20 mL×3). The combined organiclayers were washed with brine (20 mL) dried over anhydrous sodiumsulfate and evaporated to give crude product which was purified onsilica gel column chromatograph (PE/EA=100%˜60%) to give methyl5-(8-chloroimidazo[1,5-a]pyrazin-3-yl)tricyclo[3.2.2.02,4]nonane-1-carboxylate.¹H NMR (400 MHz, CDCl₃) δ=8.30 (d, J=4.7 Hz, 1H), 7.76 (s, 1H), 7.28 (d,J=5.1 Hz, 1H), 3.72 (s, 3H), 2.63-2.53 (m, 1H), 2.28-2.18 (m, 1H),2.15-1.96 (m, 3H), 1.84-1.61 (m, 4H), 1.51-1.39 (m, 1H), 1.18 (br. s.,1H), 1.05-0.98 (m, 1H), 0.88-0.79 (m, 1H) ppm.

Step 6: methyl5-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)tricyclo[3.2.2.02,4]nonane-1-carboxylate

A mixture of methyl5-(8-chloroimidazo[1,5-a]pyrazin-3-yl)tricyclo[3.2.2.02,4]nonane-1-carboxylate(120 mg, 0.362 mmol) in DMF (2 ml) was added NBS (77 mg, 0.434 mmol).The mixture was stirred at 15° C. for 1 hour. The reaction mixture waspoured into water, filtered and the cake was washed by water 3 times.The cake was dissolved in ethyl acetate (10 mL), dried over anhydroussodium sulfate and evaporated to give methyl5-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)tricyclo[3.2.2.02,4]nonane-1-carboxylate.MS: 412 (M+1).

Step7:5-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)tricyclo[3.2.2.02,4]nonane-1-carboxylicacid

A mixture of methyl5-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)tricyclo[3.2.2.02,4]nonane-1-carboxylate(130 mg, 0.317 mmol) in ammonia, H₂O (2 ml, 13.47 mmol) and 2-Propanol(2 ml) in a sealed tube. The mixture was stirred at 100° C. for 12hours. The reaction mixture was cooled to 15° C. and concentrated toafford5-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)tricyclo[3.2.2.02,4]nonane-1-carboxylicacid. MS: 377 (M+1).

Intermediate 15E1 & 15E2

(1R,2R,5R)-methyl5-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2-isopropylcyclohexanecarboxylateand (1S,2S,5S)-methyl5-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2-isopropylcyclohexanecarboxylateStep 1: dimethyl 4-bromoisophthalate

A mixture of 4-bromoisophthalic acid (20 g, 82 mmol) in 4 N HCl/MeOH(300 mL) was stirred at 60° C. for 3 hours. The mixture was concentratedand the residue was purified by column chromatography on silica gel(PE/EA=10/1) to afford dimethyl 4-bromoisophthalate.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 8.30 (d, J=1.96 Hz, 1H), 8.00 (dd,J=8.22, 1.96 Hz, 1H), 7.94 (d, J=8.22 Hz, 1H), 3.93 (d, J=5.87 Hz, 6H).

Step 2: dimethyl 4-(prop-1-en-2-yl)isophthalate

A mixture of dimethyl 4-bromoisophthalate (15 g, 54.9 mmol), potassiumtrifluoro(prop-1-en-2-yl)borate (9.75 g, 65.9 mmol), PdCl₂(dppf)-DCM(4.49 g, 5.49 mmol) and Na₂CO₃ (14.55 g, 137 mmol) in dioxane (100 ml)and water (10.00 ml) was stirred under N₂ protected at 90° C. for 2hours. The mixture was filtered and filtrate was concentrated. Theresidue was purified by column chromatography on silica gel (PE/EA=10/1)to afford dimethyl 4-(prop-1-en-2-yl)isophthalate.

¹H NMR (400 MHz, CD₃OD) δ ppm 8.36 (d, J=2.01 Hz, 1H), 8.11 (dd, J=8.03,1.00 Hz, 1H), 7.41 (d, J=8.03 Hz, 1H), 5.16 (t, J=1.51 Hz, 1H), 4.85 (s,1H), 3.94 (s, 3H), 3.88 (s, 3H), 2.10 (s, 3H).

Step 3: 3-(methoxycarbonyl)-4-(prop-1-en-2-yl)benzoic acid

To a solution of dimethyl 4-(prop-1-en-2-yl)isophthalate (12 g, 51.2mmol) in THF (100 ml) and MeOH (100 ml) was added KOH (2.87 g, 51.2mmol) at 0° C. The mixture was stirred at 25° C. for 16 hours. Themixture was adjusted to pH=6 with 1 N HCl aqueous. The mixture wasextracted with EA (200 mL×3). The EA layer was washed with NaHCO₃saturated solution. The aqueous solution was adjusted to pH=6 with 1 NHCl aqueous, and the resulting solution was extracted with EA (200mL×3). Organic layer was washed with brine and dried over anhydrousNa₂SO₄. The mixture was filtered and concentrated to afford3-(methoxycarbonyl)-4-(prop-1-en-2-yl)benzoic acid.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 8.20 (d, J=1.56 Hz, 1H), 8.03 (dd,J=8.02, 1.76 Hz, 1H), 7.41 (d, J=7.83 Hz, 1H), 5.12 (s, 1H), 4.80 (s,1H), 3.78 (s, 3H), 2.00 (s, 3H).

Step 4: 4-isopropyl-3-(methoxycarbonyl)cyclohexanecarboxylic acid

A mixture of 3-(methoxycarbonyl)-4-(prop-1-en-2-yl)benzoic acid (11 g,49.9 mmol) and PtO₂ (4.54 g, 19.98 mmol) in AcOH (500 ml) washydrogenated under 35 atm at 80° C. for 40 hours. The mixture wasfiltered and the filtrate was concentrated to afford4-isopropyl-3-(methoxycarbonyl)cyclohexanecarboxylic acid as crudeproduct, which was used in the next step directly.

Step 5: methyl5-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-2-isopropylcyclohexanecarboxylate

To a solution of 4-isopropyl-3-(methoxycarbonyl)cyclohexanecarboxylicacid (11 g, 48.2 mmol) and TEA (12.19 g, 120 mmol) in THF (200 ml) wasadded isopropyl carbonochloridate (7.09 g, 57.8 mmol) at 0° C. Themixture was stirred at 20° C. for 1 hour.(3-chloropyrazin-2-yl)methanamine hydrochloride (10.41 g, 57.8 mmol) wasadded to above solution. The mixture was stirred at 20° C. for another 2hours. The mixture was treated with water (200 mL) and EA (200 mL). Theorganic layer was washed with brine, dried, filtered and concentrated.The residue was purified by silica gel column chromatography(PE/THF=3/1) to afford methyl5-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-2-isopropylcyclohexanecarboxylateas solid. MS=354.0 (M+1)

Step 6: methyl5-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-2-isopropylcyclohexanecarboxylate

A solution of methyl5-(((3-chloropyrazin-2-yl)methyl)carbamoyl)-2-isopropylcyclohexanecarboxylate(4.3 g, 12.15 mmol) and PCl₅ (12.65 g, 60.8 mmol) in MeCN (100 ml) wasstirred at 60° C. for 2 hours. The mixture was poured into saturatedNaHCO₃ solution (250 mL), and the resulting mixture was extracted withEA (250 mL). The EA layer was separated, washed with water, brine anddried over Na₂SO₄, filtered and the solvent was evaporated under reducedpressure. The residue was purified by column chromatography on silicagel eluting with PE/THF=5/1 to give methyl5-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-2-isopropylcyclohexanecarboxylate.

MS=336.1 (M+1)

Step 7: methyl5-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-2-isopropylcyclohexanecarboxylate

A solution of methyl5-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-2-isopropylcyclohexanecarboxylate(3.3 g, 9.83 mmol) and NBS (1.749 g, 9.83 mmol) in MeCN (200 ml) wasstirred at 20° C. for 30 min. The mixture was treated with EA (200 mL)and water (200 mL). The organic layer was separated, washed with water,brine and dried over Na₂SO₄, filtered and the solvent was evaporatedunder reduced pressure. The residue was purified by columnchromatography on silica gel eluting with PE/THF=3/1 to give methyl5-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-2-isopropylcyclohexanecarboxylateas solid. MS=416.1 (M+1).

Step 8: methyl5-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2-isopropylcyclohexanecarboxylate

A solution of methyl5-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-2-isopropylcyclohexanecarboxylate(3.6 g, 8.68 mmol) in ammonia/i-PrOH (60 ml, 240 mmol) was stirred at90° C. for 16 hours in a 100 mL of sealed tube. The mixture was filteredand concentrated. The residue was purified by column chromatography onsilica gel eluting with PE/THF=3/1 to give methyl5-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2-isopropylcyclohexanecarboxylate.

Step: 9: (1R,2R,5R)-methyl5-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2-isopropylcyclohexanecarboxylateand (1S,2S,5S)-methyl5-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2-isopropylcyclohexanecarboxylate

Methyl5-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2-isopropylcyclohexanecarboxylatewas separated by SFC to give (1R,2R,5R)-methyl5-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2-isopropylcyclohexanecarboxylate¹H NMR (400 MHz, CD₃OD) δ ppm 7.50 (d, J=5.09 Hz, 1H), 6.92 (d, J=5.09Hz, 1H), 3.60 (s, 3H), 3.09-3.22 (m, 1H), 2.69-2.80 (m, 1H), 2.07-2.16(m, 1H), 1.91-2.06 (m, 5H), 1.76-1.89 (m, 4H), 1.57-1.74 (m, 2H), 0.96(d, J=6.65 Hz, 3H), 0.81 (d, J=6.26 Hz, 3H).

(1S,2S,5S)-methyl5-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-2-isopropylcyclohexanecarboxylate

¹H NMR (400 MHz, CD₃OD) δ ppm 7.50 (d, J=5.09 Hz, 1H), 6.91 (d, J=5.09Hz, 1H), 3.60 (s, 3H), 3.05-3.22 (m, 1H), 2.68-2.82 (m, 1H), 2.11 (dd,J=13.69, 3.52 Hz, 1H), 1.91-2.06 (m, 4H), 1.76-1.89 (m, 3H), 1.56-1.74(m, 2H), 0.95 (d, J=6.26 Hz, 3H), 0.80 (d, J=0.26 Hz, 3H).

Intermediate 16

(1S,3R)-methyl3-(8-amino-1-bromo-5-fluoroimidazo[1,5-a]pyrazin-3-yl)-1,2,2-trimethylcyclopentanecarboxylate Step 1: (1S,3R)-methyl3-(8-amino-1-bromo-5-fluoro-6-methoxy-5,6-dihydroimidazo[1,5-a]pyrazin-3-yl)-1,2,2-trimethylcyclopentanecarboxylate

Selectfluor (718 mg, 2.026 mmol) was added slowly to a stirred solutionof (1S, 3R)-methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1,2,2-trimethylcyclopentanecarboxylate(515 mg, 1.351 mmol) in MeOH (10 mL) and acetonitrile (10 mL). Themixture was stirred at 12° C. for 3 h. The reaction mixture wasconcentrated to remove solvent, then added water. The mixture was washedwith 2-methoxy-2-methylpropane, the water layer was added NaHCO₃ toadjust to pH=7, and then extracted with DCM. The organic layer was driedover Na₂SO₄, concentrated to give the title compound. ¹H NMR (400 MHz,CDCl₃): δ6.23-5.90 (m, 1H), 5.11-5.02 (m, 1H), 3.70 (s, 3H), 3.50-3.42(m, 3H), 3.34-3.15 (m, 1H), 2.83-2.72 (m, 1H), 2.58-2.42 (m, 1H),2.12-2.00 (m, 1H), 1.67-1.55 (m, 1H), 1.37-1.28 (m, 3H), 1.13 (s, 3H),0.83-0.78 (m, 3H) ppm.

Step 2: (1S,3R)-methyl3-(8-amino-1-bromo-5-fluoroimidazo[1,5-a]pyrazin-3-yl)-1,2,2-trimethylcyclopentanecarboxylate

To a suspension of (1S, 3R)-methyl3-(8-amino-1-bromo-5-fluoro-6-methoxy-5,6-dihydroimidazo[1,5-a]pyrazin-3-yl)-1,2,2-trimethylcyclopentanecarboxylate(700 mg, 1.623 mmol) and Cs₂CO₃ (5.29 g, 16.23 mmol) in acetonitrile (6mL) was stirred at 90° C. for 30 min in a microwave reactor. The mixturewas filtered and added water, extracted with EtOAc. The organic layerwas dried over anhydrous sodium sulfate, purified with silica gel (12 g,DCM/MeOH 10:1) to give the title compound. MS: 401.0 (M+1).

Intermediate 17

methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.2.1]octane-8-carboxylateStep 1: ethyl 8-oxobicyclo[3.2.1]octane-3-carboxylate

To a solution of 1-(cyclopent-1-en-1-yl)pyrrolidine (68 g, 496 mmol) andtriethylamine (150 g, 1489 mmol) in acetonitrile (1.09 L, dried overcalcium hydride) was added a solution of ethyl 2-(bromomethyl)acrylate(96 g, 496 mmol) in dry acetonitrile (1.04 L) dropwise. Heat wasgenerated upon addition and the solution turned reddish brown, a solidwas precipitated. The reaction mixture was heated at 90° C. for 3.5hours. Hydrolysis of the iminiumion was accomplished by the addition of150 ml of 5% aqueous acetic acid followed by a 0.5 hour refluxingperiod. The reaction mixture was cooled and an equal volume of water wasadded. The aqueous mixture was then extracted several times with etherand the combined organic layers were washed with 5% aqueous hydrochloricacid, saturated aqueous sodium bicarbonate, and saturated aqueous sodiumchloride. The resulting ethereal solution was dried over anhydrousmagnesium sulfate. Filtration and evaporation of the ether gave thecrude which was purified by column chromatography on silica gelpetroleum ether/EtOAc from 15/1 to 9/1 to get the title product. ¹HNMR(400 MHz, CD₃OD): δ 8.13-8.09 (m, 1H), 7.32-7.31 (m, 1H), 3.67 (s, 3H),2.50-2.46 (m, 1H), 2.18-2.13 (m, 2H), 1.95-1.91 (m, 2H), 1.86-1.81 (m,1H), 1.76-1.68 (m, 1H), 1.56-1.54 (m, 1H), 1.21 (s, 3H) ppm.

Step 2: 8-oxobicyclo[3.2.1]octane-3-carboxylic acid

To a solution of ethyl 8-oxobicyclo[3.2.1]octane-3-carboxylate (30.5 g,156 mmol) in MeOH/H₂O (3:1, 200 mL) was added LiOH (29.9 g, 1245 mmol).The reaction mixture was stirred at 12° C. for 2 hours. Volatiles wereremoved under vacuum, then the mixture was adjusted to pH=3.0 with asolution of 1N HCl, extracted with ethyl acetate and concentrated togive the crude title compound.

Step 3: benzyl 8-oxobicyclo[3.2.1]octane-3-carboxylate

To a solution of 8-oxobicyclo[3.2.1]octane-3-carboxylic acid (21.3 g,126 mmol) in DMF (265 mL) was added K₂CO₃ (17.5 g, 126 mmol) at 0° C.and stirred at the same temperature for 20 minutes, then(bromomethyl)benzene (23.8 g, 139 mmol) was added dropwise. The reactionmixture was allowed to warm to 12° C. and stirred for 16 hours. Thereaction mixture was added water and extracted with ethyl acetate. Theextracts were washed with brine, dried over Na₂SO₄ and concentrated togive the crude product. The crude product was purified by columnchromatography on silica gel petroleum ether/EtOAc from 15/1 to 9/1 togive the title compound. ¹H NMR (400 MHz, CDCl₃): δ 7.39-7.32 (m, 5H),5.11 (s, 1H), 3.09-3.00 (m, 1H), 2.29-2.28 (m, 2H), 2.21-2.18 (m, 4H),2.01-2.00 (m, 2H), 1.80-1.78 (m, 2H) ppm.

Step 4: benzyl 8-(methoxymethylene)bicyclo[3.2.1]octane-3-carboxylate

To a solution of (methoxymethyl)triphenylphosphonium chloride (9.98 g,29.1 mmol) in THF (100 mL) was added LiHMDS (60.1 mL, 60.1 mmol) at −78°C. Then the reaction mixture was allowed to warm to 15° C. and stirredfor 1 hour. Then the reaction was cooled to −78° C. and benzyl8-oxobicyclo[3.2.1]octane-3-carboxylate (4 g, 15.49 mmol) was added. Themixture was stirred at −78° C. for another 2 hours, then warmed to roomtemperature and quenched by NH₄Cl solution. Then the mixture wasextracted with ethyl acetate and washed with brine. The organic layerwas dried over Na₂SO₄ and concentrated under reduced pressure to affordthe crude product, which was purified by combi-flash (petroleum ether inEtOAc from 0% to 5%, R_(f)=0.68) to get the title product. ¹H NMR (400MHz, CD₃OD): δ 7.42-7.23 (m, 5H), 5.83 (s, 1H), 5.07 (s, 2H), 3.51 (s,3H), 2.99 (brs, 1H), 2.83 (tt, J=5.8, 12.0 Hz, 1H), 2.48 (brs, 1H),1.93-1.85 (m, 1H), 1.84-1.78 (m, 1H), 1.75-1.61 (m, 4H), 1.61-1.54 (m,3H) ppm.

Step 5: 3-benzyl 8-methyl icycle[3.2.1]octane-3,8-dicarboxylate

To a solution of benzyl8-(methoxymethylene)icycle[3.2.1]octane-3-carboxylate (14.6 g, 51.04mmol) in CH₂Cl₂ (160 mL) was added PCC (32.9 g, 153.1 mmol). Then thereaction was stirred at 16° C. for 2 h. PCC (11 g, 51 mmol) was added.The reaction was stirred at 16° C. for 1 h. The mixture was filtered.The filtrate was washed with water and the solid was washed with ethylacetate. The organic layer was dried over Na₂SO₄ and concentrated togive the crude product, which was purified by column chromatography onsilica gel (petroleum ether/EtOAc from 15/1 to 9/1) to give the titlecompound. ¹H NMR (400 MHz, CDCl₃): δ 7.35-7.33 (m, 5H), 5.08 (s, 2H),3.71 (s, 3H), 2.69 (s, 1H), 2.58 (s, 2H), 2.67-2.64 (m, 1H), 2.53-2.52(m, 2H), 1.95-1.88 (m, 2H), 1.80-1.78 (m, 2H), 1.71-1.67 (m, 2H),1.56-1.54 (m, 2H) ppm.

Step 6: 8-(methoxycarbonyl) icycle[3.2.1]octane-3-carboxylic acid

To a solution of 3-benzyl 8-methyl icycle[3.2.1]octane-3,8-dicarboxylate(1300 mg, 4.30 mmol) in MeOH (20 mL) was added Pd/C (80 mg, 0.676 mmol).Then the reaction mixture was purged with hydrogen for three times andstirred at 25° C. for 4 hours under 40 psi of H₂. The reaction mixturewas filtered and concentrated under reduced pressure to give the titlecompound.

¹HNMR (400 MHz, CDCl₃): δ 3.65 (s, 3H), 2.66-2.52 (m, 1H), 2.47 (d,J=4.7 Hz, 2H), 1.89-1.79 (m, 2H), 1.77-1.68 (m, 2H), 1.66-1.55 (m, 2H),1.50 (d, J=8.2 Hz, 2H) ppm.

Step 7: methyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.2.1]octane-8-carboxylate

A 30 vial was charged with8-(methoxycarbonyl)bicyclo[3.2.1]octane-3-carboxylic acid (830 mg, 3.91mmol), HATU (1784 mg, 4.69 mmol), TEA (1.635 mL, 11.73 mmol) and DCM (20mL). The mixture was stirred at 30° C. for 30 minutes. Then(3-chloropyrazin-2-yl)methanamine hydrochloride (845 mg, 4.69 mmol) wasadded, the resulting mixture was stirred at 30° C. for 16 hours. Thereaction mixture was diluted with EtOAc (50 mL) and washed with brine(50 mL×3). The organic layer was evaporated to dryness and the residuewas purified via combi flash (EtOAc in petroleum from 0% to 50%) to givethe title compound. ¹H NMR (400 MHz, CDCl₃): δ 8.46 (d, J=2.0 Hz, 1H),8.32 (brs, 1H), 6.85 (brs, 1H), 4.69-4.59 (m, 2H), 3.72 (s, 3H),2.70-2.50 (m, 4H), 2.05-1.93 (m, 2H), 1.89-1.77 (m, 2H), 1.70 (m, 2H),1.65-1.56 (m, 2H) ppm.

Step 8: methyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.2.1]octane-8-carboxylate

To a solution of methyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.2.1]octane-8-carboxylate(1 g, 2.96 mmol) in dry MeCN (10 mL) was added PCl₅ (1.85 g, 8.88 mmol).The reaction mixture was stirred at 85° C. for 1.5 hours. TLC (petroleumether:EtOAc=1:1, R_(f)=0.62) showed the reaction was completed. Then thereaction mixture was poured into cold and saturated solution of NaHCO₃(30 mL) and stirred for 5 minutes. The resulting mixture was extractedwith EtOAc (30 mL×3), the combined organic layers were dried overNa₂SO₄, filtered and evaporated to dryness to afford the crude titleproduct, which was used in the next step directly. ¹H NMR (400 MHz,CDCl₃): δ 7.88 (d, J=4.7 Hz, 1H), 7.76 (s, 1H), 7.32 (d, J=5.1 Hz, 1H),3.77 (s, 3H), 3.62-3.43 (m, 1H), 2.64 (d, J=9.4 Hz, 3H), 2.34 (t, J=12.9Hz, 2H), 1.96-1.88 (m, 2H), 1.83-1.64 (m, 4H) ppm.

Step 9: methyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.2.1]octane-8-carboxylate

To a solution of methyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.2.1]octane-8-carboxylate(935 mg, 2.92 mmol) in MeCN (15 mL) was added NBS (572 mg, 3.22 mmol).The mixture was stirred at 15° C. for 1 hour. The reaction mixture waspoured into saturated aqueous solution of NaHCO₃ and extracted withEtOAc, the organic layer was dried over Na₂SO₄, filtered andconcentrated to dryness to afford the crude title product, which wasused in the next step directly. ¹H NMR (400 MHz, CDCl₃): δ 7.94 (d,J=5.1 Hz, 1H), 7.29 (d, J=5.1 Hz, 1H), 3.77 (s, 3H), 2.62 (d, J=11.0 Hz,2H), 2.32 (t, J=12.9 Hz, 2H), 2.07-1.83 (m, 4H), 1.71 (d, J=8.2 Hz, 2H),1.67-1.54 (m, 2H) ppm.

Step 10: methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.2.1]octane-8-carboxylate

To a solution of methyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.2.1]octane-8-carboxylate (500 mg, 1.254 mmol) in 2-propanol (8 mL) was addedammonium hydroxide (8 mL, 57.5 mmol). The reaction mixture was sealedand stirred at 110° C. (the oil bath temperature) for 16 hours Thereaction mixture was concentrated under reduced pressure to afford thecrude title product, which was used in the next step directly. ¹H NMR(400 MHz, DMSO-d6): δ 7.63 (d, J=4.7 Hz, 1H), 6.95 (d, J=4.7 Hz, 1H),6.60 (brs, 2H), 3.65 (s, 3H), 2.63 (brs, 1H), 2.57-2.50 (m, 2H),2.46-2.44 (m, 1H), 1.98-1.86 (m, 2H), 1.80-1.71 (m, 4H), 1.57 (m, 2H)ppm.

Intermediate 18E1 & 18E2

(1R,3R)-3-(8-amino-1-bromo-5-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid and(1S,3S)-3-(8-amino-1-bromo-5-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid Step 1: (trans)-methyl3-(8-amino-1-bromo-5-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylate

To a solution of trans-methyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylate(1.20 g, 3.15 mmol) in AcOH (11 ml) was added NCS (462 mg, 3.46 mmol) inone portion. After the addition was completed, the mixture was stirredat 80° C. under the protection of N₂ for 3 h. The reaction was cooled toroom temperature and concentrated in vacuum to remove the solvent. Themixture was extracted with ethyl acetate (15 mL×3). The combinedorganics was dried over anhydrous Na₂SO₄, filtered and concentrated invacuum to remove the solvent. The residue was purified by columnchromatography on gel silica (PE/THF=3:1) to afford trans-methyl3-(8-amino-1-bromo-5-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylateas solid. MS: 415.1 (M+1)

Step 2:(trans)-3-(8-amino-1-bromo-5-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylic acid

To a solution oftrans-3-(8-amino-1-bromo-5-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid (1.0 g, 2.41 mmol) in DCM (50 ml) was added tribromoborane (6.82ml, 72.2 mmol) dropwise at −78° C. The mixture was stirred at 15 degreefor 40 hours. The mixture was quenched by the addition of water (20 mL)at −40° C. slowly. The resulting mixture was adjust PH=6 with Sat.NaHCO₃, the solid was collected via filtration and was dried to givetrans-3-(8-amino-1-bromo-5-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid. ¹H NMR (400 MHz, DMSO-d₆) d=8.15 (br. s., 2H), 7.19 (s, 1H), 4.02(dd, J=8.2, 16.4 Hz, 1H), 2.34 (d, J=6.7 Hz, 1H), 2.23 (d, J=12.1 Hz,1H), 2.15-1.91 (m, 4H), 1.66-1.55 (m, 1H), 0.87 (dd, J=6.5, 15.1 Hz, 6H)ppm.

Step 3:(1R,3R)-3-(8-amino-1-bromo-5-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid and(1S,3S)-3-(8-amino-1-bromo-5-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid

Thetrans-3-(8-amino-1-bromo-5-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylic acid was resolved by preparative SFC to give the(1R,3R)-3-(8-amino-1-bromo-5-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid and(1S,3S)-3-(8-amino-1-bromo-5-chloroimidazo[1,5-a]pyrazin-3-yl)-1-isopropylcyclopentanecarboxylicacid

Intermediate 19_A

Ethyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.1.0]hexane-6-carboxylateStep 1: cyclopent-3-en-1-ylmethanol

To a suspension of LiAlH₄ (6.77 g, 178 mmol) in dry THF (100 mL), wasadded cyclopent-3-enecarboxylic acid (5.0 g, 44.6 mmol) dropwise at 0°C. After that, the temperature of the mixture was warmed to roomtemperature and stirred for 3 hours. A solution NaOH (10 mL) in 10 mL ofH₂O was then added slowly and the mixture was stirred for 1 hour. Afterfiltration, the filtrate was concentrated under vacuum to givecyclopent-3-en-1-ylmethanol which was used in next step without furtherpurification. ¹H NMR (400 MHz, DMSO-d₆) δ=5.64 (s, 2H), 4.54 (t, J=5.3Hz, 1H), 3.26 (t, J=5.5 Hz, 2H), 2.38-2.27 (m, 3H), 2.09-1.98 (m, 2H)ppm.

Step 2: tert-butyl(cyclopent-3-en-1-yl)methoxy)dimethylsilane

To a mixture of cyclopent-3-en-1-ylmethanol (3.72 g, 37.9 mmol) and1H-imidazole (5.68 g, 83 mmol) in DMF (100 mL) at 0° C. was addedtert-butylchlorodimethylsilane (6.86 g, 45.5 mmol). The resultingmixture was stirred at room temperature for 18 h. The mixture wasdiluted with H₂O (200 mL), extracted with EtOAc (35 mL×2). The combinedorganic layers were dried over Na₂SO₄, concentrated and purified bycombi flash (0-5% THF/Petroleum ether) to givetert-butyl(cyclopent-3-en-1-ylmethoxy)dimethylsilane. ¹H NMR (400 MHz,CDCl₃) δ=5.60 (s, 2H), 3.44 (d, J=7.0 Hz, 2H), 2.56-2.28 (m, 3H),2.10-1.92 (m, 2H), 0.85 (s, 9H), 0.00 (s, 6H) ppm.

Step 3: ethyl3-(((tert-butyldimethylsilyl)oxy)methyl)bicyclo[3.1.0]hexane-6-carboxylate

To the solution of tert-butyl(cyclopent-3-en-1-ylmethoxy)dimethylsilane(5.45 g, 25.7 mmol) and Rh₂(OAc)₄ (0.567 g, 1.283 mmol) at 35° C. wasadded ethyl 2-diazoacetate (7.32 g, 64.1 mmol) dropwise over 5 hours.The mixture was stirred at 35° C. for 18 h. The reaction solution wasfiltered and the filtrate was concentrated in vacuo. The resultingresidue was purified with combi flash (0-5% THF/Petroleum ether) to giveethyl3-(((tert-butyldimethylsilyl)oxy)methyl)bicyclo[3.1.0]hexane-6-carboxylate.¹H NMR (400 MHz, CDCl₃) δ=4.19-4.00 (m, 2H), 3.52-3.29 (m, 2H), 1.99 (d,J=7.8 Hz, 1H), 1.93-1.79 (m, 2H), 1.76-1.63 (m, 2H), 1.61-1.49 (m, 2H),1.46-1.35 (m, 1H), 1.24 (td, J=7.1, 10.1 Hz, 3H), 0.93-0.82 (m, 9H),0.06-0.06 (m, 6H) ppm.

Step 4: ethyl 3-(hydroxymethyl)bicyclo[3.1.0]hexane-6-carboxylate

To a solution of ethyl3-(((tert-butyldimethylsilyl)oxy)methyl)bicyclo[3.1.0]hexane-6-carboxylate(4.67 g, 15.65 mmol) in THF (80 mL) was added TBAF (39.1 ml, 39.1 mmol,1.0M in THF). The reaction was heated at 50° C. for 5 hours. The mixturewas diluted with H₂O (200 mL), extracted with ethyl acetate (40 mL×3).The combined organic layers were dried over anhydrous sodium sulfate,filtered and concentrated under vacuum to give crude product which waspurified by combi flash (0-20% THF/Petroleum ether) to give ethyl3-(hydroxymethyl)bicyclo[3.1.0]hexane-6-carboxylate. ¹H NMR (400 MHz,CDCl₃) δ=4.18-4.03 (m, 2H), 3.68-3.35 (m, 2H), 2.27-2.15 (m, 1H),2.12-2.04 (m, 1H), 1.97 (dd, J=7.4, 12.5 Hz, 1H), 1.88 (br. s., 1H),1.83-1.73 (m, 1H), 1.68 (d, J=5.1 Hz, 1H), 1.63-1.51 (m, 2H), 1.25 (td,J=7.2, 11.1 Hz, 3H) ppm.

Step 5: 6-(ethoxycarbonyl)bicyclo[3.1.0]hexane-3-carboxylic acid

RuCl₃ (0.109 g, 0.524 mmol) was added to a mixture of ethyl3-(hydroxymethyl)bicyclo[3.1.0]hexane-6-carboxylate (1.93 g, 10.48 mmol)and NaIO₄ (8.96 g, 41.9 mmol) in H₂O (30 mL), MeCN (20 mL) and EtOAc (20mL). The reaction mixture was stirred at 30° C. for about 16 hours. Thereaction mixture was filtered, and the filtrate was concentrated invacuo. The residue was purified by combi flash (0-100% THF/Petroleumether) to give 6-(ethoxycarbonyl)bicyclo[3.1.0]hexane-3-carboxylic acid.¹H NMR (400 MHz, DMSO-d₆) δ=12.13 (br. s., 1H), 4.10-3.93 (m, 2H), 2.89(m, 1H), 2.17-1.97 (m, 3H), 1.93-1.83 (m, 1H), 1.80-1.72 (m, 2H),1.68-1.53 (m, 1H), 1.24-1.10 (m, 3H) ppm.

Step 6: ethyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.1.0]hexane-6-carboxylate

To a solution of 6-(ethoxycarbonyl)bicyclo[3.1.0]hexane-3-carboxylicacid (2.09 g, 10.54 mmol) in CH₂Cl₂ (60 mL) was added HATU (6.01 g,15.82 mmol) under N₂. Then (3-chloropyrazin-2-yl)methanaminehydrochloride (2.278 g, 12.65 mmol) and Et₃N (2.94 mL, 21.09 mmol) wasadded. The resulting mixture was stirred at 30° C. for 18 hours. Themixture was diluted with H₂O (100 mL), extracted with CH₂Cl₂ (30 mL×3).The combined organic layers were dried over anhydrous sodium sulfate,filtered and concentrated under vacuum to give crude product, which waspurified by combi flash (0-50% THF/Petroleum ether) to give ethyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.1.0]hexane-6-carboxylate.¹H NMR (400 MHz, CDCl_(3δ=)8.45 (br. s., 1H), 8.32 (br. s., 1H),6.95-6.65 (m, 1H), 4.67 (br. s., 2H), 4.20-4.02 (m, 2H), 3.01 (d, J=7.0Hz, 1H), 2.41-2.30 (m, 1H), 2.29-2.22 (m, 1H), 2.21-2.13 (m, 2H), 1.96(br. s., 1H), 1.90 (br. s., 1H), 1.60-1.43 (m, 1H), 1.33-1.19 (m, 3H)ppm.

Step 7: ethyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.1.0]hexane-6-carboxylate

The product ethyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.1.0]hexane-6-carboxylatewas resolved by SFC (The chiral HPLC condition was [Instrument: Thar 80;Column: Chiralpak AD-3 150×4.6 mm I.D; Mobile phase: methanol (0.05%DEA) in CO₂ from 5% to 40%, Flow rate: 2.5 mL/min; Column Temp: 38° C.;Nozzle Pressure: 100 Bar; Nozzle Temp: 60° C.; Evaporator Temp: 20° C.;Trimmer Temp: 25° C.; Wavelength: 220 nm]) to give ethyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.1.0]hexane-6-carboxylate(isomer 1)(Rt=3.83 min, 100% Area). ¹H NMR (400 MHz, CDCl₃) δ: 8.42 (d,J=2.0 Hz, 1H), 8.26 (s, 1H), 7.94 (br. s., 1H), 4.69 (d, J=5.1 Hz, 2H),4.11 (q, J=7.3 Hz, 2H), 3.36 (quin, J=10.3 Hz, 1H), 2.39-2.26 (m, 2H),2.21-2.11 (m, 2H), 2.07-1.98 (m, 2H), 1.84-1.73 (m, 1H), 1.25 (t, J=7.0Hz, 3H) ppm.

Step 8: ethyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.1.0]hexane-6-carboxylate

To a solution of ethyl3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.1.0]hexane-6-carboxylate(isomer 1) (0.18 g, 0.556 mmol) in MeCN (10 mL) was added PCl₅ (0.347 g,1.668 mmol) at 0° C. The residue was stirred at 11° C. for 1 h. Thereaction solution was poured into ice cooled sat. NaHCO₃ (aq.) (20 mL),diluted with H₂O (30 mL), extracted with EtOAc (15 mL×2). The combinedorganic layers were dried over anhydrous sodium sulfate, filtered andconcentrated under vacuum to give crude product. The crude one waspurified by combi flash (0-50% THF/Petroleum ether) to give (ethyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.1.0]hexane-6-carboxylate(isomer 1). ¹H NMR (400 MHz, CDCl₃) δ=7.85 (d, J=4.7 Hz, 1H), 7.79 (s,1H), 7.29 (d, J=5.1 Hz, 1H), 4.18-3.99 (m, 3H), 2.62-2.51 (m, 2H),2.48-2.36 (m, 2H), 2.11 (br. s., 2H), 1.90-1.81 (m, 1H), 1.28-1.20 (m,3H) ppm.

Step 9: ethyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.1.0]hexane-6-carboxylate

To a solution of ethyl3-(8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.1.0]hexane-6-carboxylate(isomer 1) (70 mg, 0.229 mmol) in MeCN (6 mL) was added NBS (48.9 mg,0.275 mmol). The residue was stirred at 15° C. for 1.5 h. The mixturewas diluted with H₂O (50 mL), extracted with EtOAc (15 mL×2). Thecombined organic layers were dried over anhydrous sodium sulfate,filtered and concentrated under vacuum to give crude product ethyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.1.0]hexane-6-carboxylate(isomer 1), which was used in next step without further purification. MS386.0 (M+1).

Step 10: ethyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.1.0]hexane-6-carboxylate

To a solution of ethyl3-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.1.0]hexane-6-carboxylate(85 mg, 0.221 mmol) (isomer 1) in 2-propanol (4 mL) andammoniumhydroxude (8 ml, 57.5 mmol) was sealed in a tube and stirred at100° C. for 18 h. LCMS showed the starting material was consumedcompletely. The reaction solution was concentrated in vacuo to give thetitle compound, which was used in next step without furtherpurification. MS: 367.0 (M+1).

Intermediate 19_B

ethyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.1.0]hexane-6-carboxylate

The title compound was obtained in an analogues manner as described forintermediate 19_A fromethyl-3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.1.0]hexane-6-carboxylate(isomer 2) (Rt=4.569 min, 93.79% Area) (obtained with chiral HPLC as thesame condition at step 7 of intermediate 19_A). MS: 367.0 (M+1).

Intermediate 19_C

ethyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.1.0]hexane-6-carboxylate

The title compound was obtained in an analogues manner as described forintermediate 19_A fromethyl-3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.1.0]hexane-6-carboxylate(isomer 3) (Rt=5.026 min, 93.79% Area) (obtained with chiral HPLC as thesame condition at step 7 of intermediate 19_A). MS: 367.0 (M+1).

Intermediate 19_D

ethyl3-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)bicyclo[3.1.0]hexane-6-carboxylate

The title compound was obtained in an analogues manner as described forintermediate 19_A fromethyl-3-(((3-chloropyrazin-2-yl)methyl)carbamoyl)bicyclo[3.1.0]hexane-6-carboxylate(isomer 4) (Rt=5.334 min, 93.79% Area) (obtained with chiral HPLC as thesame condition at step 7 of intermediate 19_A). MS: 367.0 (M+1).

Intermediate 20E1

(R)-1-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1-(3-(trifluoromethyl)phenyl)ethanol Step 1: 1-(4-chlorophenyl)-1-(3-(trifluoromethyl)phenyl)ethanol

To a solution of 1-(3-(trifluoromethyl)phenyl)ethanone (188 mg, 0.999mmol) in Toluene (10 ml) was added (4-chlorophenyl)magnesium bromide(1.199 ml, 1.199 mmol) under N₂ protection and stirred for 10 minutes.The mixture was poured into water (5 mL) and filtered. The filtrate wasextracted with EtOAc (10 mL). The organic layer was washed with brine,dried over Na₂SO₄ and concentrated in vacuo to give crude product, whichwas purified by chromatography over silica gel (4 g) (Per.Ether:THF=20:1) to give1-(4-chlorophenyl)-1-(3-(trifluoromethyl)phenyl)ethanol. ¹H NMR (400MHz, CDCl₃) δ 7.74 (s, 1H), 7.52 (d, J=7.43 Hz, 2H), 7.39-7.46 (m, 1H),7.27-7.37 (m, 4H), 2.30 (s, 1H), 1.95 (s, 3H) ppm.

Step 2: (R)-1-(4-chlorophenyl)-1-(3-(trifluoromethyl)phenyl)ethanol

The compound (R)-1-(4-chlorophenyl)-1-(3-(trifluoromethyl)phenyl)ethanoland (S)-1-(4-chlorophenyl)-1-(3-(trifluoromethyl)phenyl)ethanol wasobtained after resolved by SFC. SFC method: AD (250×30, 10 mm). MeOH:CO₂=15:85, 0.1% NH3.

Step 3:(R)-1-(4-(4,455-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1-(3-(trifluoromethyl)phenyl)ethanol

A solution of (BPin)2 (209 mg, 0.823 mmol),(R)-1-(4-chlorophenyl)-1-(3-(trifluoromethyl)phenyl)ethanol (165 mg,0.549 mmol), KOAc (162 mg, 1.646 mmol), X-Phos (26.2 mg, 0.055 mmol) andPd2(dba)3 (25.1 mg, 0.027 mmol) in 1,4-Dioxane (5 ml) was stirred at120° C. for 1 hour heated by microwave. The solution was concentrated invacuo and purified by chromatography over silica gel (4 g) (THF: pet.Ether=10:90) to give(R)-1-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1-(3-(trifluoromethyl)phenyl)ethanol.¹H NMR (400 MHz, CDCl₃) δ ppm 1.34 (s, 12H), 1.97 (s, 3H), 7.39-7.44 (m,3H), 7.52 (d, J=7.78 Hz, 1H), 7.49 (d, J=7.53 Hz, 1H), 7.72-7.83 (m,3H).

Intermediate 20 E2

(S)-1-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1-(3-(trifluoromethyl)phenyl)ethanol

The title compound was obtained in the same procedure as the otherenantisomer intermediate 20E1, using the second enantiomer in step 2 forboronic ester formation in step 3. ¹H NMR (400 MHz, CDCl₃) δ ppm 1.34(s, 12H), 1.97 (s, 3H), 7.39-7.44 (m, 3H), 7.52 (d, J=7.78 Hz, 1H), 7.49(d, J=7.53 Hz, 1H), 7.72-7.83 (m, 3H).

Intermediate 21 E1 and 21 E2

(R)-1-(3-(difluoromethyl)phenyl)-1-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)ethanol(S)-1-(3-(difluoromethyl)phenyl)-1-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)ethanol

In the same procedure as intermediate 20E1 and 20E2, starting from 1-(3(difluoromethyl)phenyl) ethanone in step 1, the two title compounds(R)-1-(3-(difluoromethyl)phenyl)-1-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)ethanoland(S)-1-(3-(difluoromethyl)phenyl)-1-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)ethanolwere prepared. LC-MS: (M+H)⁺357.2, retention time=1.24 min (D).

Intermediate 22

1-(3-ethoxy-4-(4,4,5,5-tetramethyl-1,32-dioxaborolan-2-yl)phenyl)-2,2,2-trifluoro-1-(3-(trifluoromethyl)phenyl)ethanolStep 1: methyl 4-bromo-3-ethoxybenzoate

To a mixture of methyl 4-bromo-3-hydroxybenzoate (4 g, 17.31 mmol) andK₂CO₃ (5.98 g, 43.3 mmol) in DMF (30 mL) was added iodoethane (6.75 g,43.3 mmol) dropwise. The reaction mixture was stirred at 10° C. for 8 h.The reaction was quenched with 1N HCl (100 mL), and extracted with ethylacetate (100 mL×2). The organic layers were washed with brine, driedover anhydrous sodium sulfate, concentrated to afford methyl4-bromo-3-ethoxybenzoate.

Step 2: 4-bromo-3-ethoxybenzoic acid

To a solution of methyl 4-bromo-3-ethoxybenzoate (4.1 g, 15.82 mmol) inTHF (20 mL) and MeOH (20.00 mL) was added LiOH (1.137 g, 47.5 mmol) andwater (20 mL). The mixture was stirred at 12° C. for 3 h. The reactionwas quenched with 1N HCl to pH=2 and extracted with EtOAc (100 mL×2).The combined organic layers were dried over anhydrous sodium sulfate,concentrated in vacuum to give 4-bromo-3-ethoxybenzoic acid.

Step 3: 4-bromo-3-ethoxy-N-methoxy-N-methylbenzamide

A mixture of 4-bromo-3-ethoxybenzoic acid (3.9 g, 15.91 mmol),N,O-dimethylhydroxylamine-HCl (1.863 g, 19.10 mmol), HATU (6.05 g, 15.91mmol) and DIEA (8.34 mL, 47.7 mmol) in THF (30 mL) was stirred at 10° C.for 2 h. TLC detected the reaction was complete. The reaction mixturewas quenched with sat. NH₄Cl aqueous (100 mL), extracted with EtOAc (80mL×2). The organic layer was dried over sodium sulfate, concentrated togive the crude product, which was purified by column chromatography onsilica gel (Pet. ether/EtOAc=3:1) to give4-bromo-3-ethoxy-N-methoxy-N-methylbenzamide. ¹H NMR (400 MHz, CDCl₃) δ:7.55 (d, J=8.2 Hz, 1H), 7.22 (s, 1H), 7.18-7.13 (m, 1H), 4.13 (q, J=6.9Hz, 2H), 3.54 (s, 3H), 3.35 (s, 3H), 1.47 (t, J=7.0 Hz, 3H) ppm.

Step 4: (4-bromo-3-ethoxyphenyl)(3-(trifluoromethyl)phenyl)methanone

To a mixture of magnesium (0.127 g, 5.21 mmol) and isopropylmagnesiumchloride (0.347 mL, 0.694 mmol) in THF (2 mL) was added a solution of1-bromo-3-(trifluoromethyl)benzene (0.937 g, 4.16 mmol) in THF (5 mL)dropwise at 80° C. under N₂. The solution was added to a solution of4-bromo-3-ethoxy-N-methoxy-N-methylbenzamide (1 g, 3.47 mmol) in THF (10mL) and the reaction was stirred at 15° C. for 2 h. The reaction mixturewas quenched with sat. NH₄Cl aqueous (50 mL), extracted with EtOAc (50mL×2). The combined organic phases were dried over Na₂SO₄, andconcentrated to give(4-bromo-3-ethoxyphenyl)(3-(trifluoromethyl)phenyl)methanone.

Step 5:1-(4-bromo-3-ethoxyphenyl)-2,2,2-trifluoro-1-(3-(trifluoromethyl)phenyl)ethanol

To a solution of(4-bromo-3-ethoxyphenyl)(3-(trifluoromethyl)phenyl)methanone (1.3 g,3.48 mmol) in THF (25 mL) were added trimethyl(trifluoromethyl)silane(0.743 g, 5.23 mmol) and tetrabutylammonium difluorotriphenylsilicate(0.940 g, 1.742 mmol) at 0° C. The reaction was stirred for 12 h at 14°C. under N₂. The reaction was quenched with 1M HCl (20 mL). 30 minlater, the mixture was basified with aq. NaHCO₃ (30 mL), extracted withEtOAc (20 mL×3). The organic layer was washed with brine (30 mL), driedover Na₂SO₄, evaporated to give the crude product, which was purified byflash chromatography (Pet. ether/EtOAc=10:1) to give1-(4-bromo-3-ethoxyphenyl)-2,2,2-trifluoro-1-(3-(trifluoromethyl)phenyl)ethanol.¹H NMR (400 MHz, CDCl₃) δ: 7.82 (br. s., 1H), 7.62 (t, J=7.2 Hz, 2H),7.57-7.46 (m, 2H), 7.03 (s, 1H), 6.89 (d, J=8.2 Hz, 1H), 4.09-3.99 (m,2H), 3.08 (s, 1H), 1.44 (t, J=7.0 Hz, 3H) ppm.

Step 6:1-(3-ethoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-2,2,2-trifluoro-1-(3-(trifluoromethyl)phenyl)ethanol

The solution of1-(4-bromo-3-ethoxyphenyl)-2,2,2-trifluoro-1-(3-(trifluoromethyl)phenyl)ethanol(800 mg, 1.805 mmol),4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi(1,3,2-dioxaborolane) (550 mg,2.166 mmol), potassium acetate (531 mg, 5.42 mmol) and PdCl₂(dppf) (66.0mg, 0.090 mmol) in 1,4-dioxane (15 mL) was stirred at 110° C. for 4 hunder N₂. Then it was cooled and concentrated in vacuo. The residue waspurified by chromatography on silica gel (Pet.ether:EtOAc=10:1) to give1-(3-ethoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-2,2,2-trifluoro-1-(3-(trifluoromethyl)phenyl)ethanol.¹H NMR (400 MHz, CDCl₃) δ: 7.80 (s, 1H), 7.61-7.55 (m, 2H), 7.46-7.40(m, 2H), 7.03 (d, J=7.8 Hz, 1H), 6.94 (s, 1H), 3.96 (td, J=6.6, 12.7 Hz,2H), 3.02 (s, 1H), 1.40-1.33 (m, 15H) ppm.

Intermediate 22

1-(3-ethoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1-(m-tolyl)ethanol

The intermediate 22 was prepared in the same procedure as intermediate21, using 1-bromo-3-methylbenzene as the starting material in step 4 toprovide the title compound1-(3-ethoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1-(m-tolyl)ethanol.LC-MS: (M+H)⁺ 365.1.

Example 1

(R)-4-(8-amino-1-(4-(1-hydroxy-1-(3-(trifluoromethyl)phenyl)ethyl)phenyl)imidazo[1,5-a]pyrazin-3-yl)-1,4-dimethylcyclohexanecarboxylicacid Step 1:4-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-methylcyclohexanecarboxylicacid

A solution of LiOH (201 mg, 8.37 mmol) and methyl4-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-methylcyclohexanecarboxylate(615 mg, 1.675 mmol) in Water (15 ml) and MeOH (15 ml) was stirred at60° C. for 8 hours. The solution was concentrated in vacuo and added 1NHCl to pH=2. The mixture was extracted with DCM/i-PrOH=3:1 (10 times).The combined organic was dried over Na₂SO₄ and concentrated in vacuo togive the compound4-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1-methylcyclohexanecarboxylicacid. LC-MS: (M+H)⁺ 367.1. Retention time=0.42 min (Method D).

Step 2:(R)-4-(8-amino-1-(4-(1-hydroxy-1-(3-(trifluoromethyl)phenyl)ethyl)phenyl)imidazo[1,5a]pyrazin-3-yl)-1,4-dimethylcyclohexanecarboxylic acid

A solution of4-(8-amino-1-bromoimidazo[1,5-a]pyrazin-3-yl)-1,4-dimethylcyclohexanecarboxylicacid (50 mg, 0.136 mmol),(R)-1-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1-(3-(trifluoromethyl)phenyl)ethanol(50 mg, 0.127 mmol), K₂CO₃ (56.5 mg, 0.408 mmol) and PdCl2(dppf) (19.92mg, 0.027 mmol) in 1,4-Dioxane (20 ml) and Water (5 ml) was stirred at75° C. for 2 hours under N₂ protection. The mixture was concentrated invacuo and added TFA to pH=3. The mixture was dissolved in MeCN, added 2ml TMT and filtrated. The filtrate was purified by Pre-HPLC to give thecompound(R)-4-(8-amino-1-(4-(1-hydroxy-1-(3-(trifluoromethyl)phenyl)ethyl)phenyl)imidazo[1,5-a]pyrazin-3-yl)-1,4-dimethylcyclohexanecarboxylicacid. LC-MS: (M+H)+553.2. ¹HNMR (CD₃OD, 400 MHz): d=7.93 (1H, d, J=5.6Hz), 7.85 (1H, s), 7.74 (1H, d, J=6.8 Hz), 7.50 (4H, m), 6.91 (1H, d,J=5.2 Hz), 2.55 (2H, d, J=14.0 Hz), 2.09 (2H, d, J=14.0 Hz), 2.01 (3H,s), 1.68 (2H, t, J=12.8 Hz), 1.40 (3H, s), 1.37 (2H, d, J=15.6 Hz), 1.08(3H, s) ppm.

The following Examples in Table 1 were prepared in the similar way asExample 1 following the hydrolysis of the ester and Suzuki coupling.

TABLE 1 Retention time Example Exact Mass (min, Number Structure IUPACName [M + H]+ method) 2

4-[8-amino-1-(4-{(1S)-1- hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3- yl]bicyclo[2.2.2]octane-1-carboxylic acid Calc'd 551.2, found 551.1 2.311 (C) 3

4-[8-amino-1-(4-{(1R)-1- hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3- yl]bicyclo[2.2.2]octane-1-carboxylic acid Calc'd 551.2, found 551.1 2.317(C) 4

(1S,3S)-3-[8-amino-1-(4- {(1S)-1-hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentane- carboxylic acid Calc'd 553.2, found 553.22.639(C) 5

(1S,3S)-3-[8-amino-1-(4- {(1R)-1-hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentane- carboxylic acid Calc'd 553.2, found 553.22.637(C) 6

4-[8-amino-1-(4-{(1R)-1- hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]-2,5-dioxobicyclo[2.2.2]octane- 1-carboxylic acid Calc'd 579.2, found 579.22.489(C) 7

1-[8-amino-1-(4-{(1R)-1- hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3- yl]cyclopropanecarboxylic acidCalc'd 483.2, found 483.1 2.430(C) 8

4-[8-amino-1-(4-{(1R)-1- hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3- yl]bicyclo[2.2.1]heptane-1-carboxylic acid Calc'd 537.2, found 537.2 2.193(C) 9

5-[8-amino-1-(4-{(1R)-1- hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3- yl]bicyclo[3.2.2]nonane-1-carboxylic acid Calc'd 565.2, found 565.2 2.433(C) 10

4-[8-amino-1-(4-{(1R)-1- hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]tetrahydro-2H-pyran-4-carboxylic acid Calc'd 527.2, found 527.1 2.499(C) 11

(1S,3R)-3-[8-amino-1-(4- {(1R)-1-hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]-1,2,2- trimethylcyclopentane-carboxylic acid Calc'd 553.2, found 553.2 1.930(C) 12

4-[8-amino-1-(4-{(1R)-1- hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]-2,2,5,5-tetrafluorobicyclo[2.2.2] octane-1-carboxylic acid Calc'd 623.2, found623.1 2.386(C) 13

(1R,3S)-3-[8-amino-1-(4- {(1R)-1-hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]-1,2,2- trimethylcyclopentane-carboxylic acid Calc'd 553.2, found 553.2 2.263(C) 14

(1S,3R)-3-[8-amino-1-(4- {(1S)-1-hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]-1-(1- methylethyl)cyclohexane-carboxylic acid Calc'd 567.3, found 567.2 1.956(C) 15

(1R,3S)-3-[8-amino-1-(4- {(1S)-1-hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]-1-(1- methylethyl)cyclohexane-carboxylic acid Calc'd 567.3, found 567.2 2.017(C) 16

(1S,3S)-3-[8-amino-1-(4- {(1R)-1-hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]-1,3- dimethylcyclopentane-carboxylic acid Calc'd 539.2, found 539.1 2.356(C) 17

(1R,3S)-3-[8-amino-1-(4- {(1R)-1-hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]-1,3- dimethylcyclopentane-carboxylic acid Calc'd 539.2, found 539.2 2.426(C) 18

(1S,3R)-3-[8-amino-1-(4- {(1R)-1-hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]-1,3- dimethylcyclopentane-carboxylic acid Calc'd 539.2, found 539.1 2.428(C) 19

4-(8-amino-1-{2-ethoxy-4- [1-hydroxy-1-(3- methylphenyl)ethyl]phenyl}imidazo[1,5-a]pyrazin-3- yl)bicyclo[2.2.2]octane-1- carboxylic acidCalc'd 541.3, found 541.2 2.629(C) 20

4-(8-amino-1-{2-ethoxy-4- [1-hydroxy-1-(3- methylphenyl)ethyl]phenyl}imidazo[1,5-a]pyrazin-3- yl)bicyclo[2.2.2]octane-1- carboxylic acidCalc'd 541.3, found 541.2 2.632(C) 21

(1R,2R,5R)-5-[8-amino-1- (4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl] ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]-2-(1-methylethyl)cyclohexane- carboxylic acid Calc'd 567.3, found 567.22.006(C) 22

5-[8-amino-1-(4-{(1R)-1- hydroxy-1-[3- (trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5- a]pyrazin-3- yl]tricyclo[3.2.2.0~2,4~]nonane-1-carboxylic acid Calc'd 563.2, found 563.2 2.241(C) 23

(1S,2S,5S)-5-[8-amino-1- (4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl] ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]-2-(1-methylethyl)cyclohexane- carboxylic acid Calc'd 567.3, found 567.22.163(C) 24

(1S,3R)-3-[8-amino-5- fluoro-1-(4-{(1R)-1- hydroxy-1-[3-(trifluoromethyl)phenyl] ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,2,2- trimethylcyclopentane- carboxylic acid Calc'd571.2, found 571.1 1.957(C) 25

(3-endo,8-syn)-3-[8-amino- 1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl] ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]bicyclo[3.2.1]octane-8- carboxylic acid Calc'd 551.2, found 551.22.240(C) 26

(3-exo,8-syn)-3-[8-amino-1- (4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl] ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]bicyclo[3.2.1]octane-8- carboxylic acid Calc'd 551.2, found 551.21.969(C) 27

(1S,3R)-3-[8-amino-1-(4- {(1R)-1-[3- (difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo [1,5-a]pyrazin-3-yl]- 1,2,2-trimethylcyclopentane- carboxylic acid Calc'd 535.3, found 535.22.162(C) 28

(1S,3R)-3-[8-amino-1-(2- ethoxy-4-{(1S)-1-hydroxy- 1-[3-(trifluoromethyl)phenyl] ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,2,2- trimethylcyclopentane- carboxylic acid Calc'd597.3, found 597.2 1.916(C) 29

(1S,3R)-3-[8-amino-5- chloro-1-(4-{(1R)-1-[3- (difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo [1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentane- carboxylic acid Calc'd 569.2, found 569.22.438(C) 30

(1R,3S)-3-[8-amino-5- chloro-1-(4-{(1R)-1-[3- (difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo [1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentane- carboxylic acid Calc'd 569.2, found 569.22.433(C) 31

(1S,3S)-3-[8-amino-5- chloro-1-(4-{(1R)-1-[3- (difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo [1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentane- carboxylic acid Calc'd 569.2, found 569.12.428(C) 32

(1R,3R)-3-[8-amino-5- chloro-1-(4-{(1R)-1-[3- (difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo [1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentane- carboxylic acid Calc'd 569.2, found 569.22.431(C) 33

4-[8-amino-1-(4-{(1R)-1- [3-(difluoromethyl)phenyl]- 1-hydroxyethyl}phenyl)imidazo [1,5-a]pyrazin-3-yl]-1,4-dimethylcyclohexane- carboxylic acid Calc'd 535.3, found 535.2 2.235(C)34

(1S,3R)-3-[8-amino-1-(4- {(1R)-1-[3- (difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)-5- fluoroimidazo[1,5- a]pyrazin-3-yl]-1,2,2-trimethylcyclopentane- carboxylic acid Calc'd 553.2, found 553.22.233(C) 35

(1R,3r,5S,6s)-3-[8-amino-1- (4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl] ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]bicyclo[3.1.0]hexane-6- carboxylic acid Calc'd 523.2, found 523.22.218(C) 36

(1R,3R,5S,6r)-3-[8-amino- 1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl] ethyl}phenyl)imidazo[1,5- a]pyrazin-3-yl]bicyclo[3.1.0]hexane-6- carboxylic acid Calc'd 523.2, found 523.22.180(C)

Biological Activity

The Btk inhibitor compounds of the invention having Formula I inhibitthe Btk kinase activity. All compounds of the invention have an IC50 of10 μM or lower. In another aspect the invention relates to compounds ofFormula I which have an IC50 of less than 100 nM. In yet another aspectthe invention relates to compounds of Formula I which have an IC50 ofless than 10 nM.

The term IC50 means the concentration of the test compound that isrequired for 50% inhibition of its maximum effect in vitro.

Btk Enzyme Activity Assay Methods

BTK enzymatic activity was determined with the LANCE (Lanthanide ChelateExcite) TR-FRET (Time-resolved fluorescence resonance energy transfer)assay. In this assay, the potency (IC₅₀) of each compound was determinedfrom an eleven point (1:3 serial dilution; final compound concentrationrange in assay from 1 μM to 0.017 nM) titration curve using thefollowing outlined procedure. To each well of a black non-bindingsurface Corning 384-well microplate (Corning Catalog #3820), 5 nL ofcompound (2000 fold dilution in final assay volume of 10 μL) wasdispensed, followed by the addition of 7.5 μL of 1× kinase buffer (50 mMHepes 7.5, 10 mM MgCl₂, 0.01% Brij-35, 1 mM EGTA, 0.05% BSA & 1 mM DTT)containing 5.09 pg/μL (66.67 pM) of BTK enzyme (recombinant protein frombaculovirus-transfected Sf9 cells: full-length BTK, 6HIS-tag cleaved).Following a 60 minute compound & enzyme incubation, each reaction wasinitiated by the addition of 2.5 μL 1× kinase buffer containing 8 μMbiotinylated “A5” peptide (Biotin-EQEDEPEGDYFEWLE-NH2) (SEQ.ID.NO.: 1),and 100 μM ATP. The final reaction in each well of 10 μL consists of 50pM hBTK, 2 μM biotin-A5-peptide, and 25 μM ATP. Phosphorylationreactions were allowed to proceed for 120 minutes. Reactions wereimmediately quenched by the addition of 20 uL of 1× quench buffer (15 mMEDTA, 25 mM Hepes 7.3, and 0.1% Triton X-100) containing detectionreagents (0.626 nM of LANCE-Eu-W1024-anti-phosphoTyrosine antibody,PerkinElmer and 86.8 nM of Streptavidin-conjugated Dylight 650,Dyomics/ThermoFisher Scientific). After 60 minutes incubation withdetection reagents, reaction plates were read on a PerkinElmer EnVisionplate reader using standard TR-FRET protocol. Briefly, excitation ofdonor molecules (Eu-chelate:anti-phospho-antibody) with a laser lightsource at 337 nm produces energy that can be transferred to Dylight-650acceptor molecules if this donor:acceptor pair is within closeproximity. Fluorescence intensity at both 665 nm (acceptor) and 615 nm(donor) are measured and a TR-FRET ratio calculated for each well(acceptor intensity/donor intensity). IC₅₀ values were determined by 4parameter robust fit of TR-FRET ratio values vs. (Log₁₀) compoundconcentrations.

The following Table 3 provides specific IC50 values for all theexamples. The IC50 values set forth below were determined according toAssay method described above.

TABLE 2 Compounds BTK binding potency Example BTK binding IC50 number(nM) Example 1 39.4 Example 2 5.8 Example 3 774.8 Example 4 1000 Example5 19.0 Example 6 52.0 Example 7 614.2 Example 8 1.1 Example 9 7.0Example 10 294.5 Example 11 5.0 Example 12 17.3 Example 13 86.0 Example14 1000 Example 15 104 Example 16 7.6 Example 17 55.1 Example 18 178.1Example 19 4.1 Example 20 135.6 Example 21 56.1 Example 22 6.2 Example23 28.7 Example 24 6.3 Example 25 39.9 Example 26 33.5 Example 27 0.78Example 28 1.2 Example 29 2.8 Example 30 32.3 Example 31 133 Example 3241.8 Example 33 11.4 Example 34 2.4 Example 35 15.7 Example 36 1.1

What is claimed is:
 1. A compound according to Formula I or apharmaceutically acceptable salt thereof

wherein: n is 0, 1 or 2; R¹ is (1-3C)alkyl, optionally substituted withone, two or three halogen; R₂ is independently selected from the groupconsisting of methoxy, ethoxy, halogen, and hydroxyl; R₃ is hydrogen,halogen or C(1-3) alkyl; X is selected from the group consisting of: a)cyclopropyl; b) cyclopentyl; c) cyclohexyl; d) bicyclo[2.2.2]octanyl; e)bicyclo[3.2.1]octanyl; f) bicyclo[2.2.1]heptanyl; g)bicyclo[3.2.2]nonanyl; h) bicyclo[3.1.0]hexanyl; i)tricyclo[3.2.2.0^(2,4)]nonanyl; and j) tetrahydropyranyl; eachoptionally substituted with one to four R⁴, wherein R⁴ is hydrogen, oxo,fluoro or (1-6C)alkyl.
 2. A compound of Formula 1a, or apharmaceutically acceptable salt thereof

wherein: R¹ is (1-3C)alkyl, optionally substituted with one, two orthree halogen; R² is hydrogen or (1-3C)alkoxy; R³ is hydrogen orhalogen; X is selected from the group consisting of: a) cyclopropyl; b)cyclopentyl; c) cyclohexyl; d) bicyclo[2.2.2]octanyl; e)bicyclo[3.2.1]octanyl; f) bicyclo[2.2.1]heptanyl; g)bicyclo[3.2.2]nonanyl; h) bicyclo[3.1.0]hexanyl; i)tricyclo[3.2.2.0^(2,4)]nonanyl; and j) tetrahydropyranyl; eachoptionally substituted with one to four R⁴, wherein R⁴ is hydrogen, oxo,fluoro or (1-6C)alkyl.
 3. The compound of claim 1, wherein the compoundis a compound having Formula Ib

or a pharmaceutically acceptable salt thereof.
 4. The compound of claim1, wherein the compound is a compound having Formula Ic

or a pharmaceutically acceptable salt thereof.
 5. The compound of claim1, or a pharmaceutically acceptable salt thereof, wherein R¹ is methyl,difluoromethyl or trifluoromethyl.
 6. The compound of claim 1, or apharmaceutically acceptable salt thereof, wherein R³ is fluoro orchloro.
 7. A compound selected from the group consisting of:(R)-4-(8-amino-1-(4-(1-hydroxy-1-(3-(trifluoromethyl)phenyl)ethyl)phenyl)imidazo[1,5-a]pyrazin-3-yl)-1,4-dimethylcyclohexanecarboxylicacid;4-[8-amino-1-(4-{(1S)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[2.2.2]octane-1-carboxylicacid;4-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[2.2.2]octane-1-carboxylicacid;(1S,3S)-3-[8-amino-1-(4-{(1S)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentanecarboxylicacid;(1S,3S)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentanecarboxylicacid;4-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-2,5-dioxobicyclo[2.2.2]octane-1-carboxylicacid;1-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]cyclopropanecarboxylic acid;4-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[2.2.1]heptane-1-carboxylicacid;5-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[3.2.2]nonane-1-carboxylicacid;4-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]tetrahydro-2H-pyran-4-carboxylicacid;(1S,3R)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,2,2-trimethylcyclopentanecarboxylicacid;4-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-2,2,5,5-tetrafluorobicyclo[2.2.2]octane-1-carboxylicacid;(1R,3S)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,2,2-trimethylcyclopentanecarboxylicacid;(1S,3R)-3-[8-amino-1-(4-{(1S)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclohexanecarboxylicacid;(1R,3S)-3-[8-amino-1-(4-{(1S)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclohexanecarboxylicacid;(1S,3S)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,3-dimethylcyclopentanecarboxylicacid;(1R,3S)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,3-dimethylcyclopentanecarboxylicacid;(1S,3R)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,3-dimethylcyclopentanecarboxylicacid;4-(8-amino-1-{2-ethoxy-4-[1-hydroxy-1-(3-methylphenyl)ethyl]phenyl}imidazo[1,5-a]pyrazin-3-yl)bicyclo[2.2.2]octane-1-carboxylicacid;4-(8-amino-1-{2-ethoxy-4-[1-hydroxy-1-(3-methylphenyl)ethyl]phenyl}imidazo[1,5-a]pyrazin-3-yl)bicyclo[2.2.2]octane-1-carboxylicacid;(1R,2R,5R)-5-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-2-(1-methylethyl)cyclohexanecarboxylicacid;5-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]tricyclo[3.2.2.0˜2,4˜]nonane-1-carboxylicacid;(1S,2S,5S)-5-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-2-(1-methylethyl)cyclohexanecarboxylicacid;(1S,3R)-3-[8-amino-5-fluoro-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,2,2-trimethylcyclopentanecarboxylicacid;(3-endo,8-syn)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[3.2.1]octane-8-carboxylicacid; (3-exo,8-syn)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[3.2.1]octane-8-carboxylicacid;(1S,3R)-3-[8-amino-1-(4-{(1R)-1-[3-(difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,2,2-trimethylcyclopentanecarboxylicacid;(1S,3R)-3-[8-amino-1-(2-ethoxy-4-{(1S)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,2,2-trimethylcyclopentanecarboxylicacid;(1S,3R)-3-[8-amino-5-chloro-1-(4-{(1R)-1-[3-(difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentanecarboxylicacid;(1R,3S)-3-[8-amino-5-chloro-1-(4-{(1R)-1-[3-(difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentanecarboxylicacid;(1S,3S)-3-[8-amino-5-chloro-1-(4-{(1R)-1-[3-(difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentanecarboxylicacid;(1R,3R)-3-[8-amino-5-chloro-1-(4-{(1R)-1-[3-(difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1-(1-methylethyl)cyclopentanecarboxylicacid;4-[8-amino-1-(4-{(R)-1-[3-(difluoromethyl)phenyl]-1-hydroxyethyl)}phenyl)imidazo[1,5-a]pyrazin-3-yl]-1,4-dimethylcyclohexanecarboxylicacid;(1S,3R)-3-[8-amino-1-(4-{(1R)-1-[3-(difluoromethyl)phenyl]-1-hydroxyethyl}phenyl)-5-fluoroimidazo[1,5-a]pyrazin-3-yl]-1,2,2-trimethylcyclopentanecarboxylicacid;(1R,3R,5S,6S)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[3.1.0]hexane-6-carboxylicacid; and(1R,3R,5S,6R)-3-[8-amino-1-(4-{(1R)-1-hydroxy-1-[3-(trifluoromethyl)phenyl]ethyl}phenyl)imidazo[1,5-a]pyrazin-3-yl]bicyclo[3.1.0]hexane-6-carboxylicacid; or a pharmaceutically acceptable salt thereof.
 8. A pharmaceuticalcomposition which comprises the compound of claim 1 or apharmaceutically acceptable salt thereof and one or morepharmaceutically acceptable carriers.